Basic MOSTParameter Definitions

Action Distance (A)

Action Distance (A) includes all movements through space and/or the movement or actions of the fingers, hands, and / or feet. This can take place with the hands (etc.) either loaded or unloaded.

A0 Less than or equal to 2 inches CLOSE

Here we're looking at the movement of the fingers, hands, and/or feet for a distance less than or equal to 2 inches. The time for traversing these short distances is included with the Gain Control and Placement parameters.

Example:1) The time to reach between the number keys on a packet

calculator.2) You're tasked to place washers and nuts on five bolts that are

located 1.5 inches apart.

A1 Within Reach

Within reach is exactly what it sounds like. All movements are restricted to an area described by the arc of the outstretched arm pivoted about the shoulder. You are allowed to extend this distance a bit by using body assistance -- that is, a short bending or turning of the body from the waist. You are not, however, allowed to take a step further to extend the area. This would require an A3 (one to two steps). The parameter value A1 can also apply to the leg or foot reaching to an object, lever, or pedal. However, if the trunk of the body is shifted, then the action is considered an A3.

Example:1) In a well-defined workstation, all parts and tools can be

reached without moving the body (by taking a step).

A3 One to Two Steps 1 STEP, 2 STEPS

In this case, the trunk of the body is shifted or displaced by walking, stepping to the side, or turning the body around using one or two steps. The number of steps refers to the total number of times each foot hits the floor.

A6 Three or More Steps 3 STEPS, ETC.

Additional steps are accounted for on the General Move data card for A6 (3 - 4 steps), then A10 (5 - 7 steps), and finally A16 (8 - 10 steps). Beyond that, index values for longer action distances are found in the Action Distance Table. We normally think of these values referring to the horizontal movement of the body, but they can also apply to walking up or down normally inclined stair steps. In the Action Distance Table, all of the index values are given in terms of both Steps and Feet. Surprisingly enough, research has shown that the time required to take a step is relatively constant regardless of the size of the load carried. This means that a worker uses the same amount of time to take five steps while carrying a heavy load as to take five steps with no load. But what that heavy load does is influence the step length, thereby increasing the number of steps required to cover a specific distance for a heavy load, and shorten them for a light load. What this

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tells us is that, whenever possible, action distance values should be based on the number of steps taken by the operator rather than the distance walked, as they'll be much more accurate.

If we're in our office trying to predict the time required for a new operation we won't be able to observe the operator at work. In this case, our only option is to find the action distance from distances measured at the workplace or obtained from drawings. Consequently, the distances found in the Action Distance Table are based on an average step length of 2 1/2 feet. This value is based on an average of the action distance values found in a normal manufacturing environment, So they include things like obstructed and unobstructed walking, walking up or down normally inclined stairs, and walking with or without weight. Since this figure of 2 1/2 feet represents an average, if a particular job contain several long, unobstructed and unencumbered walking distances, the action distances in the table may not represent what's actually taking place. So again, you can see that the best value to use is the number of steps actually taken by an operator.

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Body Motion (B)

When we talk about Body Motion, we're referring to either vertical (up and down) motions of the body or the actions necessary to overcome an obstruction or impairment to body movement.

B6 Bend and Arise BEND and ARISE

In this case, the body begins in an erect standing position. The trunk of the body is then lowered by bending from the waist and/or knees to allow the hands to reach below the knees. The body is subsequently returned to an upright position. The hands do not have to actually reach below the knees. Rather, the body need only be lowered enough to allow the reach to take place. There are several variations allowed under B6. Included under B6 Bend and Arise are simply bending from the waist with the knees stiff, stooping down by bending at the knees, or kneeling down on one knee.

B3 Bend & Arise, 50% Occurrence PBEND

Stacking (or unstacking) objects is where you typically see Bend and Arise, 50% Occurrence. That's because in stacking, the first few objects may require a full Bend and Arise to place the objects at floor level, but as the stack becomes taller, the last objects being stacked require no body motions at all.

B10 Sit or Stand SIT, STAND

With Sit or Stand, B10, the action taking place is either sitting down or standing up (not both) and requires a series of several hand, foot, and body motions to move a chair or stool into position. All of these motions needed to adjust the chair and the body are included in the B10. If the chair or stool is stationary and several foot and body motions are needed either to situate the body comfortably in the seat or to climb on or off the stool, then a B10 would again apply.

Sitting on a bench (without adjusting it) is a special case in which the index value of B3, Sit or Stand without moving chair, is used.

B16 Stand and Bend STAND + BEND

This is a case where a worker who has been seated stands up and walks to a location to gain control of an object placed below the knee level, where a Bend and Arise is required. This parameter variant usually shows up in the Get phase.

B16 Bend and Sit BEND + SIT

This is a case where a worker who has just performed a Bend to Gain Control of an object then Sits down prior to placing the object in it's final location. This parameter variant usually shows up in the Put phase.

B16 Climb On or Off CLIMB, DESCEND

The climbing on or off being referred to is for a work platform approximately three feet high. The parameter involves using a series of hand and body motions to lift or lower the body. To climb onto a platform one first places one hand on the edge and then lifts the knee to the platform. This is followed by placing the other hand on the platform and bending forward (to shift body weight forward), which then allows the other knee to

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be lifted onto the platform. The maneuver is completed by rising from both knees. Climbing off the platform consists of performing all of this in reverse order.

Example:

1) Climb onto a tractor frame on an assembly line to tighten a bolt.

B16 Passing Through Door DOOR

In order to walk through a door one must reach for and turning the handle, open the door, walk through the door, and then close the door. All the paces required to travel the distance to accomplish these steps are included in the B16 value, which applies to virtually all hinged, double, or swinging doors.

Example:

1) An operator walks seven steps to a door, passes through the door, and walks two steps to a desk where a heavy object is picked up and placed on the floor two steps from the desk.

All of the steps taken (seven to the door and two to the desk) are part of getting the object. The proper application of B16 requires adding the steps before and after the doorway to allow a single action distance value for nine steps (A16). The steps to actually pass through the doorway are included as part of the B16 value. The appropriate analysis for this example is:

A16 B16 G3 A1 B6 P1 A0 430 TMU's

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Gain Control (G)

To Gain Control (G) means that we want to have complete manual control of an object. This is done mainly with the finger(s), hand(s), and foot/feet The G parameter can include one or several short-move motions used to gain full control of the object(s) before it is to be moved to another location.

G1 Light Object GRASP (optional)

This first type of grasp is the one we will run into most often. The object to be grasped may be jumbled with other objects, lying close against a flat surface, or simply lying by itself. The simplest way to gain control is by touching the object with the fingers, hand, or foot (contact grasp). Or, with certain restrictions, a more difficult grasping action may be involved like that needed to pick one object out of a jumbled pile of objects. Either one or two hands may be used as long as only one object is obtained and that object can be simultaneously grasped by both hands. G1 will also apply if several objects are grouped together or arranged in such a way that they may be picked up as one object.

Examples:

1) Pick up pliers from a table.2) Using both hands, pick up a rock lying by itself.3) Pickup welding rods grouped together in a holder (several

objects grouped as one). 4) Obtain one bolt from a box full of bolts.5) Grasp a lever, crank, knob, toggle switch, pushbutton, foot

pedal, or other activating device (to be applied in the Controlled Move Sequence Model).

6) Obtain one sheet of sandpaper from the top of a workbench.7) With a hand already touching a penny, grasp the penny with

the same hand in order to lay it aside. 8) Obtain one bolt from a jumbled pile of bolts.

G1 Light Objects Simo GRASP (optional)

The idea behind Light Objects Simo is that different body members perform manual simultaneously. So, for example, one hand might gain control of a light object (G1), while the other hand gains control of another light object (G3). Then the total time required is no more than that to gain control of one light object.

Example:1) Pick up a calculator and pencil using both hands.2) Using both hands, pick up a screwdriver and screw lying next

to each other. 3) Using both hands, pick up two large suitcases.

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G3 Light Object(s) Non Simo GET

The case of Light Object(s) Non Simo is a case where one hand must wait on the other in grasping an object, which means that a larger index value will result. It could be the operator is attempting to gain control of two separate objects, or maybe of one object at two different points.

Performing simultaneous motions is largely dependent on the amount of practice an operator has had. In a practical sense, that means that for a worker in a job shop simultaneous motion opportunities will be limited. This is because the operator has little practice opportunity to gain the automatic skills necessary to perform simultaneous motions before the job is finished. On the other hand, a worker in an automobile plant will have no trouble developing coordinated motion because of the number of cycles involved in performing the job.

In practice it is easy to distinguish between Simo and Non Simo parameters by simply observing their appearance

G3 Heavy or Bulky GET

If one picks up a heavy object, there is always a certain amount of hesitation before sufficient muscular force is brought to bear to move the object. Things like weight, shape, and size also influence the amount of time required to gain control.

Many things influence this delay, to include the weight of the object, it's location with respect to the body, the existence of handles or grips for easy grasping, or even the strength of the individual. Even a small, light object, if it is poorly located, may induce a delay due to the need to acquire balance or additional muscular control for leverage.

So, any time one looks at the time involved with gaining control of a heavy object, weight is not the most important criteria. Rather, the hesitation or pause needed for the muscles to tense or the body to stiffen prior to moving the object is what's most important.

Examples:

1) Get hold of a lawn mower engine located on the shop floor.2) Take hold of a loaded wheelbarrow before pushing.3) Get hold of a set of golf clubs on the airline baggage claim

system by reaching over other people's suitcases.4) Brace your body before pushing a piano across the room.5) Pick up a large garbage can to lift it into a pickup truck bed.

The weight, shape, or size of an object can also affect the method of gaining control in that one may have to move or reorient the object first. Techniques like sliding the object closer to the body first, the use of several intermediate moves, or finding a temporary grip on the object may have to be used with this type of object.

G3 Blind or Obstructed GET, FREE

There are times when an operator cannot directly see the object to gain control of it, leading to the use of a G3 Blind or Obstructed. If the location is blind, the operator must feel around for the object before it can be grasped. If obstructed, the fingers or hand must be worked around the obstacle before reaching the object.

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Examples:

1) Laying on your back under a car, locate a bolt on the engine in a location you cannot see.

2) Work the fingers around the wiring in an electrical assembly to get a part (obstructed).

3) Take your keys out of your pocket.

G3 Disengage DISENGAGE

To gain control with the parameter variant disengage implies that the object is somehow "stuck" in it's current location and that sudden recoil will take place when it does disengage. Significant muscular force has to be applied to free the object from its surroundings, and when it does recoil, the object must follow an unrestricted path through the air (not to be confused with unseating a lever, crank, or other controlled devices).

Examples:

1) Disengage a tightly fitting socket from a ratchet tool.2) Remove a knife stuck in wood.3) Disengage the cork from a wine bottle.

G3 Interlocked FREE

The parameter variant interlocked implies that the object is intermingled or tangled with other objects and must be separated or worked free before complete control is achieved.

Examples:

1) Remove a crowbar from a crowded toolbox (the crowbar is buried beneath other tools.

2) From a box of paperclips, gain control of one paperclip that is tangled with another.

G3 Collect COLLECT

With the parameter variant collect we are trying to gain control of several objects which may be jumbled together in a pile or spread out over a surface. If the objects are jumbled, we may gain control of several of them by digging down into the pile with the hand(s) and bringing up a handful. On the other hand, if they are spread out, the objects may be swept together with the hand(s) and fingers and picked up as one object.

G3, Collect, also covers the case where the hand is picking up two objects in close proximity to one another. However, if more than two are to be picked up, then either a series of G1 's or additional G3 grasping actions need to be applied. Of course, this also means that additional reaches (A1) will be required

Examples:

1) Get a handful of change from your pocket.2) Gather up a pen, pencil, and eraser spread out on a

desk with one sweeping motion of the hand. 3) Grasp a handful of screws from a box.4) Collect several sheets of paper lying on a table.

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Placement (P)

When we talk about placement we're referring to what takes place when the object arrives at its target location. So within this parameter we're looking at actions taken to align, orient, or engage the object with another before releasing control. The index value for displacement is chosen according to how difficult the object is to locate at its final destination. A limited amount of insertion (up to 2 inches) is included in the definition, while for insertions greater than this, a combination of General Move and Controlled Move sequences must be used.

P0 Pickup Object(s) PICKUP, CARRY

If no placement occurs, like when an object is picked up and held, then P0 is appropriate. In this case, the placement takes place later in the sequence model.

P0 Toss Object(s) TOSS, THROW

This is another case where no placement occurs as the object is released during the movement of the object (during the action distance parameter).

Examples:

1) Toss a finished part into a tote bin.2) Toss a completed assembly down a drop chute.3) Throw balled-up paper into a trash can.

P1 Lay Aside MOVE

This is a very common type of placement. Here the object is laid aside in only an approximate location. It is not aligned to anything, there is no adjustment of it's location, and it's placement requires very little involvement on the part of the operator..

Examples:

1) Lay a wrench aside after loosening a bolt.2) Place a pen on top of a desk.3) After finishing reading, lay your textbook down on

the coffee table.

P1 Loose Fit PUT

Now, during placement of the object, we're concerned about where specifically it ends up, but the tolerances involved are very loose. As a result only a very modest amount of mental, visual, or muscular control is necessary to place it. The clearance between the engaging parts is loose enough so that a single adjusting motion, without the application of pressure, is required to seat or position the object.

Examples:

1) Place a washer on a bolt.2) Replace a telephone receiver on the hook.3) Put a coat hanger on a rack.

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P3 Adjustments PLACE, REPLACE

When looking at P3, Adjustments, we see a case where several corrective actions are needed to bring the object to it's final location. This could be of difficulty in handling the object, closeness of fit, lack of symmetry of the engaging parts, or uncomfortable working conditions. This case can be identified by recognizing these obvious efforts, hesitations, or correcting motions at the point of placement to align, orient, and/or engage the object.

Examples:

1) Place a key in a door lock.2) Align a prick punch to scribe a mark.

P3 Light Pressure PLACE, REPLACE

Still a P3, the Light Pressure case could have been a P1 with respect to positioning, however, because of close tolerances or the nature of the placement, the operator must apply force to seat the object.

Examples:

1) Place a moist stamp on an envelope.2) Press a thumbtack into a corkboard.3) Insert a car cigarette lighter.

P3 Double PLACE, REPLACE

In the case of the Double, two distinct placements take place during the placement activity.

For example, to assemble two parts held by a fixture, a bolt is first placed through a hole in both parts before the nut is placed on the bolt with the other hand. The first placement occurs with the bolt through the holes followed by a second placement of the nut on the bolt.

This parameter can also be applied to an object being lined up to two different marks following a general move, as long as the marks are less than 4 inches apart. Otherwise, a P6 would apply.

Examples:

1) Place an original on a photocopy machine.

P6 Care or Precision POSITION, REPOSITION

With a P6, Care or Precision, the placement is so difficult that it takes place in what is obviously slow motion. This level of care is needed because of the high degree of concentration required for mental, visual, and muscular coordination.

Examples:

1) Thread a needle.2) Position a soldering iron to a crowded circuit

connection.

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P6 Heavy Pressure POSITION, REPOSITION

As a result of very tight tolerances, not the weight of an object alone, a high degree of muscular force is needed to engage the object. Occurring only rarely in practice, heavy pressure can be easily recognized as the regrasping of an object, tensing of the muscles, and the preparation of the body prior to the application of pressure.

You may have noticed this already, but the weight of an object is not what drives the index value for P (placement). Rather, it's the difficulty of the placement. For example, a heavy suitcase laid to rest on the floor, has an index value of P1 (lay aside), whereas a light package, squeezed into a tight space between two other boxes on a shelf, is a P6 (heavy pressure).

Examples:

1) Position a book in a very tight slot on a bookshelf.

P6 Blind or Obstructed POSITION, REPOSITION

The P6, Blind or Obstructed parameter occurs because the operator cannot see the point of placement, or an object obstructs reaching the target. Of course, if the target is blind, the operator must feel their way to that location. If simply obstructed, they must work the fingers and / or hands around any obstacles to reach the target location. Either one of these conditions slows the operator down.

Examples:

1) Place a nut and washer on a hidden bolt.2) Position a spark plug in an engine block after

working the hands between the distributor wiring.

P6 Intermediate Moves POSITION, REPOSITION

Sometimes the only way to arrive at a target location is to make several intermediate moves. This can happen because of the nature of the object, like in the case of a heavy, bulky, or hard to handle object. Or it could be due to the conditions surrounding the object that prevent direct placement at the target location.

Examples:

1) Carry a washing machine into a house, place it down on the floor, and "walk it" into position.

2) Place tables in a classroom by first setting a table down and then aligning it with several sliding moves.

3) Place a heavy or bulky box on a pallet and stack neatly.

4) Place a splined shaft into a gearbox.

A special case of this variant occurs when placing one object from a handful of different objects in the palm. For example, from a handful of different size nails and screws one is to select a single 16d nail and place it in the palm. Before actually placing the object, several finger and hand movements are required to select and shift one of the objects (the 16d nail) from the palm to the fingertips. To do this, the hand must first be turned over to allow visual selection of the appropriate object. Several complex finger motions (intermediate moves) are needed to shift the object up to the fingertips before placement can occur.

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If the objects in the hand are not different, this case, (P6), will not work since no visual selection will need to take place. This means that regrasp can normally occur during the action distance to place the object (no additional regrasp time needed). On the other hand, if the action distance in the Put phase is 2 inches or less (A0), then a regrasp (G1), should be used.

Examples:

1) From a handful of change, use the thumb to push a dime to the fingertips and place it in a vending machine.

2) Using the thumb, select a 1/2 - inch washer from a handful of assorted washers and nuts and place it on a bolt.

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Special Parameter Variants

The data cards in the MOST system cannot take into account every activity observed in normal production situations. Two of the more common exceptions not covered on the data card are covered next. The fact that they're not on the data card doesn't mean they're unimportant, but rather, just rare.

B3 Sit or Stand Without Moving Chair STAND-SIMPLE, SIT-SIMPLE

There are situations where the body can sit or stand without moving a chair that's involved. In that case a B3 would be appropriate. Note that this value covers either sit or stand, but not both.

Examples:

1) Stand up from a sitting position on a high school bleacher seat.

2) Sit down in a theatre seat.

P3 Loose Fit Blind PLACE

Another rare event, the Loose Fit Blind, occurs when an operator must feel around for the placement location before a loose placement can occur.

Examples:

1) Place a pencil into an inside coat pocket.

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Parameter Frequencies

The General Move Sequence cannot cover every possible motion without some modification, as one or more parameters within the General Move Sequence occur more than once. This activity is shown on the sequence model by placing parentheses around the parameters that are repeated and writing the number of occurrences in the frequency column of the calculation sheet, also within parentheses.

Example:

Get a handful of washers from a bin (within reach) and place on four bolts (within reach) located 5 inches apart.

A1 B0 G3 (A1 B0 P1) A0 (4)

A1 Reach to washersB0 No body motionG3 Collect a handful of washers

A1 Reach to place washerB0 No body motionP1 Place washer, loose fit

A0 No return

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Move Controlled (M)

The General Move dealt with movement of an object following an unrestricted path. With Move Controlled (M), the path that the object follows is tightly controlled. Index values for the M parameter are listed on the Controlled Move data card under the categories Push / Pull / Pivot" and "crank

M1 One Stage < 12 inches PUSH, PULL

The first M parameter is for the case of movement of the fingers, hands, or feet a distance less than or equal to 12 inches.

Examples:

1) Engage the feed on a milling machine with a short hand lever.2) Depress the clutch pedal on a truck with the foot.3) Open a hinged lid on a small jewelry box.4) Push a pencil 8 inches across a table.

M1 Button / Switch / Knob PUSH, PULL, ROTATE

Most machines have some type of device like a button, switch, or knob that controls their function. This device is normally activated by a short pressing, moving, or rotating action of the fingers, hands, wrist, or feet.

Examples:

1) Press a telephone redial button.2) Activate an automobile turn signal switch.3) Turn a doorknob.

M3 One Stage > 12 inches SLIDE, TURN, OPEN, SHUT

This parameter is similar to the first movement parameter, except that displacement is achieved by a movement of the hands, arms, or feet exceeding 12 inches. No walking is allowed though, so that the maximum displacement covered by this parameter occurs with the extension of the arm plus body assistance.

Examples:

1) Push a box across conveyor rollers.2) Roll a desk chair 3 feet between the computer and the desk.3) Close a file drawer by pushing it shut.

M3 Resistance, Seat / Unseat PRESS, SEAT, UNSEAT

Objects needing to be moved sometimes exhibit a lot of resistance to moving. This resistance may prior to, during, or following the Controlled Move. This parameter variant covers the muscular force applied to "seat" or "unseat" an object or, if necessary, the short manual actions employed to latch or unlatch the object.

Examples:

1) Disengage the emergency brake on an automobile.2) Twist on a radiator cap securely.

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M3 High Control SLIDE, TURN

By definition, a Controlled Move takes place over a controlled path. However, there are degrees of control that need to be maintained, which gives rise to the parameter High Control. In this case, a specific orientation or alignment of the object must be maintained during the Controlled Move. The parameter is characterized by a higher degree of visual concentration (eye contact between the object and its surroundings) and slower movements to keep within tolerance requirements or to prevent injury or damage.

Examples:

1) Turn the dial on a combination lock to a specific number.2) Slide a fragile item carefully across a workbench.3) Carefully slide a plank toward a running table saw blade.4) Set a cup full of hot water on a table within reach.

M3 Two Stages < 12 inches PUSH + PULL, SHIFT

This case, Two Stages < 12 inches, is a more specialized case in which an object is moved in two directions (or increments) a distance less than or equal to twelve inches per increment without relinquishing control.

Examples:

1) Engage and subsequently disengage the feed on a cutting machine with a short hand lever.

2) Open and subsequently close a small toolbox.3) Shift from the first to the third gear of a manual gearshift.

M6 Two Stages > 12 inches or with one-two steps OPEN + SHUT, OPERATE, PUSH OR PULL WITH 1, 2 PACES

This parameter is just like the last, except that now the distance exceeds twelve inches per stage without relinquishing control.

Examples:

1) Open and subsequently close a cabinet door.2) Raise and lower the cover of a copying machine.

This parameter also covers the situation where the operator must travel one or two steps in order to move the object. Notice that index values are based on number of steps, and not on the distance traveled. This is because the number of steps taken will increase (shorter steps) with higher levels of resistance, and visa-versa

It's also possible that in moving an object in two stages, that one stage will be greater than twelve inches in length, and the other less than twelve inches. In a case like this, the total distance moved for the two stages must be estimated. If the total distance exceeds 24 inches an M6 will be assigned; for less than 24 inches, and M3 is the proper index value.

Examples:

1) Reach to a lever and, without relinquishing control, push it forward 6 inches and then to the side 20 inches.

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M10 Three to Four Stages or with Three - Five Steps MANIPULATE, MANEUVER, PUSH OR PULL WITH 3, 4, 5 PACES

This parameter, and the next, are just more complicated cases of what we've already seen. Here an object is displaced in three or four directions or increments without relinquishing control or it is pushed / pulled.

Examples:

1) From the reverse position, shift to the first gear on a four-speed automobile transmission

2) Set the feed/speed selector on an engine lathe.3) Push box on conveyor belt walking four paces.

M16 Move Controlled with Six-Nine Steps PUSH OR PULL WITH 6, 7, 8, 9 PACES

Finally, here we look at a case where we push or pull object(s) with six-nine steps. Of course, we need not stop there. If the number of steps exceeds nine than we simply refer to the table for Push or Pull extended values

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CRANK

Move Controlled consists of the categories "Push / Pull / Pivot" and "Crank", so this is the second of them. This category refers to the manual actions used to rotate objects like cranks and hand wheels in a circular path more than half a revolution. Less than half a revolution is considered a "Push/Pull/Pivot.

The index values listed for "crank" cover the time needed to apply sufficient force to unseat / seat the crank or engage / disengage a device being cranked in addition to the time for the cranking action itself. All index values are for the number of revolutions completed (rounded to the nearest whole number).

Examples:

1) Move a milling machine carriage by cranking a handwheel.2) Turn over a Model T engine by cranking on it.

PUSH-PULL CRANKING PUSH, PULL, PUSH+PULL

Every once in a while, "cranking" is not really cranking. If a method of cranking will result in back-and-forth movement of the elbow instead of pivoting at the wrist and/or elbow, then it's treated as a "push-pull". In this case, M1 parameter applies, or M3 if there is substantial resistance, and the pushes and pulls are counted and considered to be that many applications of the M1 parameter. It will always be more efficient to use pivotal cranking instead of push-pull (reciprocal) cranking.

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PROCESS TIMES (X) PTIME OR PT (NO.) HOUSE/MINUTES/SECONDS/TMUS

Process times are those times that are under the control of the machine or process and not the operator. We're assuming here that process times have a fixed, repeatable time and are less than two minutes. Also, a good rule of thumb is for the process time to be no more than 20 percent of the cycle time (manual plus machine time). The Index Value table for Process Times lists the index value that corresponds to the observed or calculated "actual time".

Should a process time be long, as is usually encountered in machining, then appropriate equations should be used to calculate those times. For cycles over ten minutes in length, the process time should not exceed two minutes in order to maintain a consistent level of accuracy. If the process time exceeds these limits, the discrete value should be allowed on a separate line as "Process Time" (PT).

Care must be taken to record the index value for the time observed in the sequence model, and not the actual clock time.

Examples:

1) There is a process time of 6 seconds between the time a button is pushed and the time a shear cuts off a piece of sheet steel.

2) After the switch is turned on, there is a warm-up period before the TV set warms up. (NOTE: They used to work that way.)

3) A punch press cycles in 1.5 seconds after the palm buttons are hit.

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ALIGNMENT (I)

Alignment is what takes place when we arrive at the target location. It refers to manual actions taken to achieve an alignment or specific orientation of objects.

If an object must be closely controlled during its move, then that falls under the M parameter variant for High Control. However, if the object must be lined up to one or more points after the Move Controlled, then the Alignment parameter comes into play.

The (single) eye of the average person can take in an area described by a circle 4 inches in diameter at a normal reading distance of about 16 inches from the eyes. Within this circle, a person can align an object to two points without any additional time for movement of the eyes. Once outside this four inch circle, the times for alignment go up as the eyes shift back and forth between the two points as the object is adjusted to complete the alignment. The area of normal vision is therefore the basis for defining most of the Alignment parameter variants.

I1 To One Point LOCATE

This is the simplest type of Alignment as the object need be aligned to only one point. It is used when a single correcting action will satisfy our need for precision. This variant is similar to the P1 variant except that I1 occurs following an M in Controlled Move. The P1 occurs following an A in General Move.

I3 To Two Points < 4 inches Apart GUIDE

We know from the field of view of an average person's eye that the area of a 4 inch diameter circle is the most we can see without having to readjust the eyes to align objects. So this case, To Two Points < 4 Inches Apart, reflects this fact. In aligning to two points it is assumed that more than one correcting motion will be necessary, and this time is built into the parameter variant.

I6 To Two Points > 4 inches Apart GUIDE + ADJUST

Once we cross over the 4 inch circle barrier, the time to align objects lengthens due to all the extra eye movements involved. And so, in this parameter variant several correcting motions and eye focuses are included to allow the time for the hand-eye coordination to be accomplished.

I16 Precision ALIGN-ACCURATE

This case, Precision, comes into play whenever multiple points must be aligned with an object, or extreme precision is called for in an alignment. For example, the actions to align a French curve or a drawing template with several points require an I16.

Whenever a Controlled Move involves the Alignment activity, the preceding M parameter is used to describe only the distance the object travels, either < 12 inches (M1) or > 12 inches (M3). Also, we use the alignment parameter only when it follows a Controlled Move. Should a two step process be involved where the object is first moved to an area and then aligned as a separate step, the General Move Placement (P) would be the correct selection. Of course, that would be obvious since we'd be dealing with a General Move, not a Controlled Move, as the first step of this two step process.

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MACHINING OPERATIONS

Because we're using MOST to look primarily at manufacturing, it's worth mentioning that there are also a special group of Alignment parameter variants that are frequently encountered in machine shop operations. They're not found on the Controlled Move data card since they apply only to machining, and the card applies to all types of operations.

I3 To Workpiece GUIDE

The first of these special Alignment parameter variants is for aligning a machine tool to the workpiece prior to making a cut. Normally, cranking action (M) is used to bring the cutting tool into position, and then the crank or handwheel is manipulated so that the cutting edge of the tool just touches the workpiece.

I6 To Scale Mark GUIDE + ADJUST

This is very similar to the parameter variant To Workpiece, except of course that we're aligning To (a) Scale Mark. The reason for the difference in time between the two is that it's assumed that more care is taken in aligning to a scale mark than to a workpiece. So included in this parameter variant is time several taps on the fist of the hand (holding the handwheel) to tweak the alignment.

I10 To Indicator Dial ALIGN

The parameter variant, To Indicator Dial, is similar to the first two, but the level of precision is even more demanding, as reflected by the tasks to be performed by the operator. Following any cranking actions (M) to locate the tool near the cutting position, the machine operator must visually locate the indicator dial, read the indicator setting, and carefully adjust the tool to the correct setting by tapping the hand that holds the handwheel several times with the other hand.

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Alignment of Nontypical Objects

A nontypical object would be an object that is large, flimsy, sharp, or require special handling, and are the types of objects normally seen with press, shear, or cut-off operations. The alignment of an object like this typically requires several short correcting motions (< 2 inches), and is quite often made to stops, guides, or some type of mark. However, sometimes the presence of stops negates the need for adjustments in which case the alignment value will be zero. The alignment parameter values are based on the number of adjustments needed to properly line up the object.

If an object is extremely heavy where the feet must be shifted prior to the next movement, the value for alignment of nontypical objects will apply. If object(s) can be realigned without shifting the feet, the original values will apply. In addition, separate Controlled Moves should be used since the alignment values do not include time to move the body or gain control of the object.

Examples:

1) A press operator moves a 4 foot by 8 foot sheet of thin gauge steel, which is flimsy, a distance of 14 inches. The steel sheet must be aligned to two stops on opposite ends of the sheet. It is not necessary for the operator to reposition the hands during the activity. The operator must take one step back to gain control of the sheet.

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THE TOOL USE SEQUENCE Parameter Definitions

F Fasten

This parameter is used to establish the time for manually or mechanically assembling one object to another, using the fingers, a hand, or a hand tool.

L Loosen

This parameter is used to establish the time for manually or mechanically disassembling one object from another using the fingers, a hand, or a hand tool.

C Cut

This parameter covers the manual actions employed to separate, divide, or remove part of an object using a sharp-edged hand tool (knife) and related activities using pliers.

S Surface Treat

This parameter covers the activities aimed at removing unwanted material or particles from, or applying a substance, coating, or finish to, the surface of an object.

M Measure

This parameter includes the actions employed in determining a certain physical characteristic of an object by comparison with a standard measuring device.

R Record

This parameter covers the manual actions performed with a pencil, pen, chalk, or other marking tool for the purpose of recording information.

T Think

This parameter refers to the eye actions and mental activity employed to obtain information (read) or to inspect an object, including reaching to touch when necessary to feel the object.

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The Fasten / Loosen Data Card

Fasten or Loosen includes manually or mechanically assembling or disassembling one object to or from another using the fingers, a hand, or a hand tool. Index values for the F and L parameters are grouped according to the body member (finger, wrist, arm) performing the work, with an additional category for power-operated tools.

With the exception of power tools, all the data on the data card refer to the number of actions performed by the respective body member during either a Fasten (F) or Loosen (L) activity. An action is defined as the back-and-forth or up-and-down movement of the fingers, wrist, or arm to perform one "stroke", "pull", or "tap" with the tool. In the case of the crank data, action refers to one revolution of the tool.

Finger Actions (Spins or Cranks) SPIN(S)

Finger actions refers to using the fingers to roll or spin an object (like a nut) between the thumb and index finger so as to attach or detach it from a fastener

Example:

1) Attach a nut to a bolt with the fingers.2) Turning a machine screw with a screwdriver.

The Finger Spin information on the data card includes time for the light application of pressure for seating or unseating a fastener, but due to the limited strength of the fingers, does not account for final tightening. The times do include one or two wrist turns at the end of the finger spin when resistance typically increases. If more than two wrist turns are needed, then those additional turns need to be addressed separately.

In some situations, the finger spin action converts into a finger crank action typified by turning a wing nut on a bolt with the forefinger held straight and pivoted at the base joint. Each 360 degree turn would be counted as one SPIN.

Wrist Actions

Wrist Actions is a general classification that includes Wrist Turns, Wrist Stroke, Wrist Crank, and Tap. It means that a twisting motion of the wrist is used on the fastener. This action is about the axis of the forearm or the pivoting of the hand from the wrist with either a circular or back-and-forth motion. This motion typically includes hand movements up to 6 inches in length as measured from the knuckle at the base of the index finger.

Wrist Turn(s) WRIST-TURN(S)

The first of the Wrist Actions, Wrist Turns covers the use of tools like screwdrivers, ratchets, and T-wrenches that are not removed from the fastener during use and are not repositioned on the fastener after an action. The data on the Tool Use data card for Wrist Turns includes the time for repositioning the hand or tool handle after each action. Also, the wrist is powerful enough that final tightening or initial loosening can be accomplished with the wrist turn, so the index values assigned from the wrist turn column also include the time for final tightening or initial loosening of a fastener.

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Wrist Stroke (with reposition) WRIST-STROKE(S)

When using a wrench one must reposition the tool after each stroke before making the next stroke, and it is this method that is termed the wrist stroke. The index values on the data card refer to the number of power strokes with the wrench. Just like the wrist turn, the data for wrist actions includes times for final tightening or initial loosening. Tools covered by this parameter include fixed end, adjustable, and Allen wrenches (tools that are normally repositioned on a fastener during use).

Wrist Crank WRIST-CRANK(S)

Wrist Crank is a very efficient form of Wrist Action that can be used to quickly fasten or loosen a fastener. Under certain circumstances either wrenches or ratchets can be used when there are no obstructions in the path of the tool to spin or rotate it around a fastener while remaining affixed to it. It will only work, though, in cases where the operation being performed offers little or no resistance, and because of this, the times on the data card do not include the time for final tightening or initial loosening of a fastener. This must be accomplished by using wrist turns or wrist strokes, and maybe a combination of these to fully analyze the motions involved. Index values for wrist cranks cover the number of revolutions performed with the tool.

Tap TAP(S)

Although it might not at first appear to be a Wrist Action, the use of a small tool like a hammer in combination with several short tapping motions is. That's because under Tap, the hand is pivoted at the wrist to strike the part and tap it into place. Data in this column include the number of tapping actions made with the hand.

Arm Actions

Arm Actions is a general classification that includes Arm Turn(s), Arm Stroke(s) (with reposition), Arm Crank(s), Strike, and T-Wrench (Two Hands). Arm Actions are executed by having wrist relatively rigid, and pivoting the forearm from the elbow with an up-and-down, circular, or back-and-forth motion, with from pivoting the upper arm from the shoulder if need be. Included in Arm Actions are hand movements of between 6 and 18 inches in length or a circular motion with a diameter up to 24 inches.

Arm Turn(s) ARM-TURN(S)

The first of the Arm Actions is the Arm Turn which covers only the use of a ratchet. This type of turn occurs when the ratchet is held near the end of the handle so that one is pulling on the tool. Index values from the arm turn column include time for the final tightening or initial loosening that may occur in the complete fastening or loosening activity.

Arm Stroke(s) (with Reposition) ARM-STROKE(S)

The second type of Arm Action, the Arm Stroke, is similar to the Wrist Stroke. It applies to the normal method of using tools like fixed end wrenches, adjustable wrenches, and Allen wrenches. Where with each stroke or pull on the tool, the wrench must be removed and repositioned again on the fastener before making a subsequent pull. The index values for Arm Stroke apply to the number of arm actions (pulls) performed with the wrench. The index values for arm strokes allow for the final tightening or initial loosening that may occur.

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Arm Crank(s) ARM-CRANK(S)

Arm Crank is a third type of Arm Action that to tools used with a circular movement of the forearm as it is pivoted at the elbow or the shoulder. Similar to the Wrist Crank, the hand is used to push the tool around the fastener and can take place only if there is minimal resistance and there are no obstructions in the tool path. Also like the Wrist Crank, the time values on the data card do not include the time for final tightening or initial loosening of a fastener, and refer to the number of revolutions with the tool.

Strike STRIKE(S)

Strike is similar to Tap under Wrist Actions, except that in using the hammer one pivots the arm from the elbow while leaving the wrist fixed. The data shown on the data card refer to the number of up-and-down motions performed.

T-Wrench (Two Hands) TWO-ARM-TURN(S)

The last category under Arm Actions it T-Wrench (2 Hands). It's not found on the Tool Use data card, but instead is a supplemental table. The arm actions given in the table refer to the number of 180-degree turns of the T-wrench, and include the time for reaching with each hand to the opposite handle before making the next turn. The data also allow for any final tightening or loosening to be completed. This would also be appropriate for turning a large valve or other such item with both hands.

Power Tools INCH(ES), CM

Power Tools form a third category on the Fasten / Loosen side of the Tool Use data card. Covering both electric and pneumatic tools, the index values are based on the time required to attach or detach a fastener to a length of one to two times the diameter of the fastener. This is the distance to hold a nut securely. Two values are found in the table: F3 or L3 for a screw diameter of 1/4 inch or smaller, and F6 or 6 for larger screws up to and including one inch in diameter. So, for a standard fastener, the index value is simply dependent upon the diameter of that fastener.

When running down or out longer fasteners, where more threads are needed to hold the item or threads are fine, a frequency can be applied to the F or L value chosen. For example, run in a 3/8 inch diameter bolt one inch. Normally, the bolt would be run in approximately 3/4 inch, or two times its diameter, and an F6 would be appropriate. However, in this case it is being run in three to four times its diameter. An F6 times two is now appropriate.

Supplementary values for special tools or special situations not found on the data card have been developed and are presented here.

F6 Torque Wrench ARM-TURN

This first category of torque wrench is for one whose handle length is up to 10 inches. The data value on the data card is for one arm action and includes the time either to align the dial or to await the click.

F10 Torque Wrench LONG-ARM-TURN

The second category of torque wrench is for those whose handle is 10 - 15 inches in length. Again, the table value is for one arm action and includes the time either to align the dial or to await the click.

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F16 Torque Wrench EXTRA-LONG-ARM-TURN

The last torque wrench category is for those whose handle length is 15 - 40 inches. The value is for one arm action and includes the time either to align the dial or to await the click.

Tool Placement

The subject of Tool Placement deals with placement of the tool or object in the working position prior to the tool action. The index values for these placements are found in the Tool Placement Table, which was generated from the General Move data card.

So, for example, using the fingers or hands as a fastening / loosening tool is a P1. Using those same fingers or hands to place a fastener, though, becomes a P3, and if the placement is blind or obstructed, a P6.

In a similar fashion, we see that the use of a fixed wrench is a P3, while an adjustable wrench is a P6, and an adjustable wrench already set to size in a prior operation is a P3.

There may or may not be an initial placement of a hammer prior to any tapping or striking actions. Normally, if a hammer is being used to drive small nails or tacks, the hammerhead will be positioned over the nail (P1) prior to performing any actions. In many cases, however, no initial placement of the hand or hammer is necessary (P0), for example, before simply tapping or striking a larger object or surface area.

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The Data Card for Cut, Surface Treat, Measure, Record, and Think

The back side of the Fastening / Loosening Tool Use data card the parameters of Cut, Surface Treat, Measure, Record, and Think. This data is representative of the operations performed in many industries, but is not comprehensive. Values can be added to suit a particular situation or industry.

Cut

Cut is a category that describes the manual actions employed to separate, divide, or remove part of an object using a sharp-edged hand tool. The values for the C parameter cover the use of pliers, scissors, or knife for general cutting and related activities.

Pliers

Pliers is the first parameter in the category of Cut. Three different methods are detailed for cutting through wire using pliers. The particular method employed largely depends on the hardness of the wire material and the diameter or gauge of the wire.

C3 Soft CUTOFF SOFT

This parameter applies to cutting a soft steel, copper, or other small-gauge wire. Recognized by squeezing the pliers with one hand and making one cut.

C6 Medium CUTOFF MEDIUM

This parameter applies to cutting a steel wire or cable and can be recognized by using the pliers with one hand and making two cuts. Following an initial cut, the pliers are rotated around the wire and repositioned over the cut before completely cutting through the wire.

C10 Hard CUTOFF HARD

This parameter applies to cutting a heavier wire (approximately 10 gauge) and can be recognized by following the method for a Medium Cut, but also using two hands to make the two cuts.

C1 Grip GRIP

This is a special subcategory of Cut where we're not actually cutting, but using the pliers to hold an object. Following the initial placement of the pliers, the operator squeezes the pliers to simply hold an item and subsequently releases the pressure on the item.

Example:

1) Using pliers, hold a wire in place for soldering.

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C6 Twist TWIST

Still talking about the parameter Cut, Twist involves closing the jaws of the pliers on two wires, and with two twisting motions joining the wires together. If more than two twisting motions are required, then they have to be collected into groups of two (twists) and have a frequency applied to them.

Example:

1) Using pliers, twist the ends of two wires together.

C6 Form Loop FORM-LOOP

Form Loop is another type of twisting action in the operator closes the jaws of the pliers on a wire and using two actions bends a loop or eye in the end of the wire.

Example:

1) Using pliers, form an eye in the end of a wire to fit over a terminal in a junction box.

C16 Secure Cotter Pin SECURE-COTTER-PIN

A last type of twisting action with a pliers an operator bending both legs on a cotter pin to hold it in position.

Example:

1) Using pliers, bend legs on a cotter pin to secure it through a small shaft.

Scissors CUT(S)

Scissors still operates under the category Cut, and applies to cutting paper, fabric, light cardboard, or other similar material using scissors. Index values are selected by counting the number of cuts or scissors actions used in cutting an object. Placement of a scissors is normally a P1 (P3 if exact placement is required).

Knife SLICE(S)

Just as an object can be cut with a scissors, it can also be cut with a knife. In general, the index value chosen is based on the number of slices made with the knife. So, for example, three slices with a knife give an index value of C10. The use of a sharp knife for cutting string or light cord carries the index value C3. Any individual slice can be up to 32 inches long. Placement of a knife uses a P1 most of the time with a P3 for a precise cut.

Surface TreatSurface Treat is the next activity on the back of the Tool Use data card. It

includes cleaning material or particles from a surface, or applying a substance, coating, or finish to the surface of an object. Surface Treatment includes lubricating, painting, cleaning, polishing, gluing, coating, and sanding, to name a few. The times on the data card are limited to general cleaning activities that are performed with a rag or cloth, an air

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hose, or a brush. Other kinds of surface treatment activity, if encountered, may be treated as special tools and supplementary index values developed for those particular activities.

The cleaning tools covered by the S parameter include:

1) Air hose or nozzle for blowing small particles or chips out of a hole or cavity or from a surface.

2) Brush for brushing particles, chips, or other debris from an object or surface.

3) Rag or cloth for wiping light oil or a similar substance from a surface.

The index values for Surface Treat are based on amount of surface area to be cleaned. One exception is the cleaning of a hole or cavity in a part, jig, or fixture with an air hose, in which case the value S6 (point or cavity) is appropriate. If more than one cavity is cleaned in this manner, the value S6 along with the P parameters, and an action distance (A) to account for the distance between cavities is used. Multiply this distance by the number of cavities.

Another exception is the brush cleaning of a small object, in which case an S6 is appropriate. A small object refers to brushing a jig, fixture, or cavity.

Measure MEASURE

Measure is exactly what it sounds like. The index values for the M elements cover all actions necessary to place, align, adjust, and examine both the measuring device and the object during the measuring activity. Because any needed precision comes with the use of the tool, this tool placement (P) is with a P1.

M10 Profile Gauge PROFILE-GAUGE

A profile gauge is used to compare the profile of an object to that of the gauge. It can be used to verify angles, radii, screw-pitch, and a variety of other things. The M10 value includes placing and adjusting the gauge to the object, plus the visual actions to compare the configuration of the object with that of the gauge.

M16 Fixed Scale FIXED-SCALE

This parameter covers the use of a linear (yardstick, etc.) or an angular (protractor) measuring device. The value M16 includes adjusting and readjusting the tool to two points and the time to read the actual dimension from the graduated scale.

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M16 Calipers < 12 inches CALIPER

This parameter covers the use of Vernier calipers up to 12 inches in capacity. The M16 value includes setting the caliper legs to the object dimension, locking the legs in place, and reading the Vernier scale to determine the measurement.

M24 Feeler Gauge FEELER-GAUGE

This parameter covers the use of a feeler gauge to measure the gap between two points. The M24 value includes fanning out the blades, reading and selecting the appropriate blade size, and positioning the blade to the gap to check for fit.

M32 Steel Tape < 6 feet STEEL-TAPE

This parameter covers the use of steel tape to measure the distance between two points. It covers measurements up to six feet only because it makes no allowance for the operator walking or otherwise moving. The M32 value includes pulling the tape from the reel, positioning the end of the tape, adjusting and readjusting the tape between the two points, the time to read the dimension from the scale, and finally pushing the tape back into the reel.

M32 / M42 / M54 Micrometers < 4 inches

Three different types of micrometers, each with a capacity of 4 inches, are covered here. The index value, M32 covers measuring depth (keyword DEPTH-MICROMETER), M42 is used for measuring outside diameter (NO. INCH-OD-MICROMETER), and M54 is for measuring inside diameter (NO. INCH-ID-MICROMETER). The values include setting the micrometer to the part, adjusting the thimble for fit, locking the device, and finally reading the Vernier scale to determine the dimension. Placement of the tool is a P1 since all adjustments of the tool are included within the M parameter.

Record

Record is another of those parameters that is what it sounds like. It covers the actions performed with a writing instrument or marking tool to record information. The index values for Write apply to the normal-size handwriting operations (script or print) performed with a pen, pencil, or other writing instrument. The Mark data covers the use of such marking tools as a scribe, felt market, or chalk, for the purpose of identifying or making a larger mark (1 - 3 inches) on an object.

Write WRITE (NO.) DIGIT(S), WORD(S)

Write covers the use of digits or words, and is meant to cover the routine recording of information in shop operations. Index values are based on the number of digits (letters or numbers), or the number of words written down. A special case consists of writing the date or writing one's signature, both of which are considered an R16.

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Mark MARK (NO.) DIGIT(S)

These data apply to marking or identifying an object or container using a marking tool, such as a scribe or felt marker. Each "mark" is counted as a digit. The index values for marking digits apply to printed characters (letters and numerals) of 1 - 3 inches in size. Other common marking values include making a check mark (R1) and a scribing line (R3).

The placement of a pen, etc. before writing or marking is a P1. If a line is to be drawn that requires precise placement, a P3 might be required.

Think

The category Think refers to the use of sensory mental processes, particularly those involving visual perception, and may also include "reaching to feel an object". It includes both Inspection and Reading. Most of the time what would pass for "think" occurs simultaneously with other operations, and so has no effect on the time to perform a task. However, there are always exceptions, and so "think" is provided for on the data card.

Inspect INSPECT

The parameter Inspect covers only simplistic inspection processes where go, no-go type decisions are being made. The index value in the table refers to the number of points on an object to be inspected, and covers locating those points and then making quick decisions about conforming to quality requirements.

Except for reaching to feel an object, these parameter values do not cover the manual handling of the object that may occur during the inspection. Caution should be exercised in using these or any inspection values since, quite often, these types of inspections are performed simultaneously with other activities, and in fact, that's preferred.

In addition to visual inspection, values are provided for the activities of Touch for Heat (T6), where the hand is moved to the object, moved over the surface of the object, and removed, as well as Feel for Defect (T10), where the hand is moved to the object, moved over three surfaces of the object, and removed.

Read READ (NO.) DIGIT(S), SINGLE-WORD(S), WORD(S)

Reading is exactly what it sounds like, and is further subdivided into "digits or single words" and "text of words".

Digits or Single Words is used for reading technical data such as part numbers, codes, quantities, and dimensions from a blueprint. A digit is considered a letter, a number, or a special character. The index number is the number of digits or single words read.

Text of Words is used when analyzing situations in which the operator is required to read words arranged in sentences or paragraphs. The index values are based on the number of words, and are based on an average reading rate of 330 words per minute or 5.05 TMU per word.

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T3 Gauge

Use when a device is checked to see if the pointer is within a clearly marked tolerance range.

T6 Scale Value

A specific quantity is read from a graduated scale, such as a measuring stick or a temperature - pressure gauge.

T6 Date / Time

The month, day, and year are read from a document or calendar. The time of day is read from a clock or wristwatch.

T10 Vernier Scale

Visually locate and read (only) an exact value from a micrometer, caliper, or similar device. This does not contain time for placing and setting the device to an object.

T16 Table Value

A specific value is located and read from a table after scanning the table horizontally and vertically.

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