MIT5312: Professor KirsProject Management Slide 1 An Overview of Project Management Chapter 4 of the...

MIT5312: Professor Kirs Project Management Slide 1

An Overview of Project Management

Chapter 4 of the Text(With variations)


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I want to build a bookcase that will look like this:

VeryVery, , VeryVery Simple:• 1” x 10” Pine Boards• The side pieces are about

3’ high• The lower shelf should be

about 4” from the ground

• Each shelf should hold a normal book, say 12”

• Each shelf will have 2 screws holding it on each side, so there will be a total of 3*2*2 = 12 screws

• The top shelf should be 3” below the top of the side

Very Cheap to Make !!


If we were to look at all the individual components, it might look something like:

3 @ 1” x 10” x 30”

2 @ 1” x 10” x 35”


Of course, I need to cut the pieces of pine from three 6’ boards:

30”35”6¾”

4178”

Waste


1. Go to the store and get the materials necessary

3. Drill the holes for the screws

4. Screw in the screws

2. Cut the wood

So, What Activities do you need to perform to build your bookshelf ???

5. Have a glass of wine and admire the beautiful bookcase

I thought about this in advance!! Here is what I will have to do:

What?? Me Worry ??


How long did it would take you to build the bookcase ???

Well, for the 1st Activity: Go to the store and get the materials necessary:

Depends, sometimes I can find everything right away, and be in and out of there in 10 minutes. I once spent 3 hours there. Usually, about a half-an-hour, I guess.

Usually, I can get to Home Depot in 15 minutes, although I could probably make it in 10 minutes, or, if traffic is bad and I just miss all the lights, it could take as much as 30 minutes.

What about getting the materials needed ???


How long to cut the wood ???

That could be tricky. I’ve got to line them up first. Probably 20 minutes. Where is that drill?? I saw it the other day. If I can find it right away, and everything falls into place, it might only take 10 minutes, otherwise, it might take 40 minutes.

To drill the holes ???

Oh, piece of cake. I can do it in 5 minutes. If I can find the saw (my garage is a mess). probably 10. Where is that saw?? OK, 20 minutes, maybe 25 …. Tops.

To screw in the Screws ???Easy. What, 1 minute a screw? That’s 12 Minutes. Quicker if I use the electric screw-driver. 6 minutes. Where is that? Alright, 20 minutes if I have to look for the regular screw-driver and use that.


Those are all the activities ???Yeah, what else is there?

It doesn’t take any time to design the bookcase ???Oh, of course. That took a lot of time. Probably an hour. Maybe two. But if I had been really focused on it, I probably could have come up with a plan in about 15 minutes.

After you are done shopping, don’t you have to drive back home ???Well, obviously. OK, so the same guidelines that I applied to driving to the store apply for the drive home.

When you get home, don’t you have to unload the materials ???But that doesn’t take long. 5 minutes. Maybe 3. Unless I have to go to the bathroom first, in which case it might take 10.


Before you cut the wood, don’t you measure it ???

Well, Of course. You think I’m dumb or sumtin’? I always measure twice. That might take 10 minutes, give or take a minute.Do you need to sand the wood ??

Oh yeah, I forgot. I’d probably sand the whole boards first, then cut them, then sand the ends. I’d probably do a some fine sanding after I put the the whole thing together.

How long would that take ??

Hmm, I don’t know. Maybe an hour, all tolled. I suppose it could take half that time if the wood is really good, or maybe an extra 45 minutes if the wood is bad.


Shouldn’t you also careful determine where you should drill the holes before you do ???You do think I’m stupid, don’t you? That takes a long time, or it can. You have to measure and mark both of the sides. If you get lucky, it might only take 5 minutes. If you run into problems, it might take 20 minutes. Probably 15 minutes, on average.

Don’t you want to stain the wood afterward ???Alright, you win!! Maybe I am stupid! OK, I do want to stain it. Two coats. Easy, though. 20 minutes per coat, give or take 5 minutes. I have to wait about 1 hour between coats, however.

Are you going to varnish after that ???Stop!! You’re hurting me!! OK – one coat. 15 Minutes, give or take 3 Minutes. OK - Maybe 10 more minutes if I have trouble opening the can. Then I have to wait 8 hours for it to completely dry.

The Wine ???DROP DEAD !! I’m starting now !!


OK - Now what ??The exact order of all activities needs to be determined:

Plan Bookshelf

Go to Store

Buy Materials

Drive Home

Unload Car

Sand Wood

Measure Wood

Cut Wood

Determine where to Drill

Drill Holes

Screw-in screws

First Coat of stain

Wait for it to dry

Second Coat of Stain

Wait for it to dry

Varnish

Wait for it to dry


So how long long will it take you to complete the whole project ???Whatever I said before!

Which times? If everything goes well? The Average Times? The worst-case-scenarios?How do you determine something like that?

It is not easy, but we might assume a normal distribution (we can be proven wrong Later):

Which implies that we could calculate the expected value (expected time to complete the project) as:

Best-Time + (4 * Average-Time) + Worst-Time

6OR

a + 4m + b

6(For the sake of Simplicity)

Why the 6??


Isn’t that the same thing as just taking the average time ??It could be, but it might not be. Let’s look at estimated times:

Activity Optimistic Time Probable Time Pessimistic Time Expected TimePlan Bookshelf 15 minutes 60 minutes 120 minutes 62.50 minutes

Buy Materials 10 minutes 30 minutes 180 minutes 51.67 minutesDrive Home 10 minutes 15 minutes 30 minutes 16.67 minutes

Go to the store 10 minutes 15 minutes 30 minutes 16.67 minutes

Unload Car 3 minutes 5 minutes 10 minutes 5.50 minutesSand Wood 30 minutes 60 minutes 105 minutes 62.50 minutes

Cut Wood 5 minutes 10 minutes 25 minutes 11.67 minutesDetermine where to drill 5 minutes 15 minutes 20 minutes 15.00 minutes

Measure Wood 3 minutes 5 minutes 10 minutes 5.50 minutes

Drill Holes 10 minutes 20 minutes 40 minutes 21.67 minutesScrew in the screws 6 minutes 12 minutes 20 minutes 12.33 minutesStain #1 5 minutes 20 minutes 5 minutes 20.00 minutesWait before restaining 60 minutes 60 minutes 60 minutes 60.00 minutesStain #2 5 minutes 20 minutes 5 minutes 20.00 minutes

Varnish 12 minutes 15 minutes 25 minutes 20.00 minutesWait for it to dry 480 minutes 480 minutes 480 minutes 480.00 minutes

Total Time: 729 minutes 902 minutes 1,225 minutes 941.67 minutes

Wait before Varnishing 60 minutes 60 minutes 60 minutes 60.00 minutes

N0 – Not quite the same!


So – What does this mean ??• IF everything goes perfectly, it will take 729 Minutes

• In the worst Case scenario, it will take 1,225 Minutes

• In should take 902 Minutes

• In all likelihood, we expect it to take 942 Minutes

(12 hours and 9 minutes)





Shouldn’t we add-on some extra time, just in case something goes wrong ??

That is the whole idea of basing our time on Expected times.

But even so, shouldn’t we assume that it will take longer ??We could – but it defeats the purpose schedule planning

Eventually, we expect our estimates to improve due to:• Increased attention to detail• Experience• Organizational Learning

How much will this cost you ???


HA! I know this:

Didn’t you also use some stain and Varnish, not to mention the brushes, paint thinner, sandpaper, rags and other supplies ???

HA, again! I already had those things in my garage!!

But you still had to initially buy them, and will have to replenish them when they run out. How much did they initially cost, and what portion of the materials did you actually use ???

• 3 six-foot pieces of 1” x 10” Pine: 3 * 10.95 = 32.85• Twelve 1½” Aluminum Screws: + 2.95

35.80Not Bad, for a solid wood bookcase, huh??? The same thing

costs nearly $100 at Walmart !!


OK, OK – No big deal:

Item Price % Used CostSandpaper 4.95 10 0.50Rags 1.99 20 0.40Stain 6.49 50 3.25Varnish 4.89 33 1.61Brush 0.89 100 0.89

Total: 6.65

A little more than I expected, but the total cost is still good.

What about the depreciation on the tools you used ??

Oh, Come On!! I could build a hundred bookcases, two hundred, maybe 300, using those tools !! The shop vacuum, next to nothing !!


Alright – If it will make you happy:

Item Price % Used CostCircular Saw 59.97 0.33 0.20Power Drill 49.45 0.33 0.16Shop Vacuum: 129.00 0.03 0.04

Total: 0.40

See !! I said it was no big deal! The total cost is still really good:

• Cost of Wood and Screws: 35.80• Cost of additional Supplies: + 6.65

+ 0.40• Depreciation:42.85

Well … pretty good


No Taxes ???Oh! 8¼ percent: 42.85 * 1.0825 = 46.39

But its still really nice !!

What about the cost of getting the Material ???Well, that’s not really a big deal, but the government estimates about $0.30/mile, and its 4 miles, so:

46.39 + 8 * 0.30 = 48.79

Do you work for free ???Absolutely NOT! I have a Ph.D. and earn over $5.00/hr ! Call it $6.00

48.79 + 6 * 15.7 = 112.99

Next time, I’m going to Walmart !!


The example illustrates some of the problems associated with project management:• Poor Estimating• Overoptimism

• Premature Commitment to a fixed budget and schedule

Other frequently encountered problems include:• Failure to establish upper management support• Lack of organizational commitment• Taking shortcuts through or around the system development• Poor expectations management

• Mythical Man-Month Assumptions• Scope Creep • Feature Creep

• Inadequate People Management Skills• Failure to adapt to business change• Insufficient Funds


There are (basically) only five (5) attributes that need be considered:

• The system Information is acceptable to Management

• The system Information is acceptable to Users• The system is delivered “on Time”

NOTICE that we did not say that the system was excellent

What does constitute Project Success ???

• The system is delivered within the agreed-upon budget

• The development of the system does not interfere sith on-going business operations

(there are other measures for system performance)


Project Management Tools• Our Initial Example might be a little too simple:

• It only involves one person (me)• All the Activities are sequential (one must be completed

before the next one can begin)

• Let’s assume the following situation:

Manuel, Mohammad, and Jackson have decided to go into business together. The first thing they have to do is find an office and move in. Manny, Mo, and Jack will share all of the responsibilities. They have decided they need to perform the following activities:• Locate the Office• Interview Potential Staff• Hire and train the staff• Select and Order the Furniture

• Remodel & Install Phones• Set-Up Furniture• Move In


Project Management Tools• In this case some things can be done at the same time:

• They can Look for an Office, Interview Potential Staff Members and Select the Office Furniture at the same time

• They can Remodel and Install the Phones and Set-up the Furniture and Hire and Train the Staff at the same time, BUT only after they have selected an office, Interviewed the potential staff, and selected the furniture

• They can Move In Only after they have Selected an Office, Remodeled and Installed the Phones and Set-up the Furniture (they could still continue Interviewing and Hiring staff, if need be)


Project Management Tools• We could initially set this up as a Work-Breakdown

Structure:Office Set-Up Project

Level 1 Activities Locate an Office Select/Order Furniture Interview Staff

Level 2 Activities

Remodel & Install Phones

Set-up Furniture Hire and Train Staff

Level 3 Activities Move In

• The Chart shows the sequence of activities, but NOT necessarily which activities can be done concurrently


Project Management Tools• We need to look at what activities must Precede an activity,

and, once again, how long each activity will take, in terms of Optimistic, Pessimistic, Average, and Expected time

• After intense questioning of Manny, Mo, and Jack, we find:

Activity Description Precursors Worst Time Best Time Ave. Time Expected

A Locate Office ---- 6 Weeks 1 Day 2 weeks 11.8 Days

B Select & Order Furniture ---- 5 Days 1 Day 2 Days 2.3 Days

C Interview Potential Staff ---- 6 Weeks 1 Day 3 Weeks 15.2 Days

D Remodel & Install Phones A, B 3 Weeks 3 Days 2 Weeks 9.7 Days

E Set-up Furniture A, B 3 Days 1 Day 2 Days 2 Days

F Hire and Train Staff C 2 Weeks 3 Days 1 Week 4.2 Days

G Move In D, E, F 2 Days 1 Day 1 Day 1.2 Days

Totals: 95 Days 11 Days 50 Days 46.4 Days

* Manny, Mo and Jack Don’t work on weekends, so a week is 5 Days

Notice that these are ridiculous figures since activities may be performed concurrently


Project Management Tools• We can now (at least) better map out our Schedule using a

Gantt Chart:

Activity DescriptionA Locate OfficeB Select & Order FurnitureC Interview Potential StaffD Remodel & Install PhonesE Set-up FurnitureF Hire and Train StaffG Move In

Day: 0 1 2 3 4 5 6 7 8 91 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

2 0

2 1

2 2

Meaning we should finish in about 22 days


Project Management Tools• Of course, this is still not very exact:

• Unless we are very precise in graphing, our estimates could be off

• We can get much more precise estimates using a technique called Project Evaluation Review Technique (PERT)

• In its simplest form, it basically states that If we know When an activity can begin, and how long that activity takes, we can estimate When it will end

Wow …. Now THAT is just sheer genius …..

• It does imply that we must keep track of two things:• Events, or when an activity begins and ends• Activities, or the task at hand


PERT

• We know, for example, that Activity E (Furniture Set-up) can begin only after Activities A (Locating an office) AND B (Selecting and Ordering the furniture) have been completed

• Let’s assume:• Event 1 is the time at which we can start Activity A• Event 2 is the time at which we can start Activity B• Event 3 is the time at which we can start Activity E

• Because BOTH activities A and B must be complete before we can start C, Event 3 must therefore also be the time at which activities A and B must be completed:

3

1

2

A

BC

Where the Circles represent the Events and the lines represent the Activities


PERT• Let’s Look at our Project a little more closely:

11.8

1

2

A

Event 1 Indicates the beginning of our Project (i.e., Time Zero)

Event 2 Indicates the end of Activity A

We EXPECT Activity A to take 11.8 Days

If the Start Time (ST) for activity A is at time 0, and we expect it to take 11.8 days to complete, then the Earliest Finish (EF) time for activity B is 11.8 days.ES = 0

EF = 11.8

EF = ST + E(t) = 0 + 11.8 = 11.8

(The Earliest time we can Start (ES) any activity)

(i.e., Locate an Office)

Similarly, the ES time for any activity beginning at event 2 is 11.8 Days

ES = 11.8


PERT• Adding on the some of the other activities and events:

11.8

1

2

A

ES = 0

32.3

B

Activity B (Select and Order Office Furniture) also starts at event 1 (time 0), is expected to take 2.3 days to complete, will be completed at event 3, meaning the Earliest Finish (EF) time for activity B is 2.3 days.

EF = 2.3

15.2

4

C

Activity C (Interview Potential Staff) also starts at event 1 (time 0), is expected to take 15.2 days to complete, will be completed at event 4, meaning the EF time for activity B is 15.2 days.

EF = 15.2

EF = 11.8ES = 11.8

The ES time for any activity starting at event 3 is also 2.3 Days

ES = 2.3

And the ES time for any activity starting at event 4 is also 15.2 DaysES = 15.2


PERT

• Let’s add Activity D (Remodel and Install Phones):

11.8

1

2

A

ES = 0

32.3

B

15.2

4

C

Activity D can start at event 3 (ES = 2.3 days), is expected to take 9.7 days to complete, will be completed at event 5: EF = ES + E(T) = 2.3 + 9.7 = 12 Days

ANDES = EF = 12 Days

5 9.7

D

EF = 12.0

EF = 15.2ES = 15.2

EF = 2.3ES = 2.3

EF = 11.8ES = 11.8

ES = 12.0


PERT

11.8

1

2

A

ES = 0

32.3

B

15.2

4

C

5 9.7

D

EF = 12.0

EF = 15.2ES = 15.2

EF = 2.3ES = 2.3

EF = 11.8ES = 11.8

ES = 12.0

Wait!!! Doesn’t Activity D begin only after BOTH activities A and B have been completed ???

• True – We must change the diagram so that Event 3 Reflects the fact that BOTH A and B have been Completed

0 An Activity that takes 0 Time ???

• The activity is a Dummy Activity, meaning it doesn’t really exist

• It is used only for diagramming purposes


PERT

11.8

1

2

A

ES = 0

32.3

B

15.2

4

C

5 9.7

D

EF = 12.0

EF = 15.2ES = 15.2

EF = 2.3ES = 2.3

EF = 11.8ES = 11.8

ES = 12.0

0

But if Activity D cannot begin until both A and B are complete, and A can not be finished until day 11.8, How can D start at day 2.3 ???

• It can’t – we need to readjust Event 3’s Earliest Starting Time (ES)

• The earliest an event can start equals the longest time it takes to complete any activity which ends at that event


PERT

5 9.7

D

• We can recalculate our Diagram ES and EF times as:

EF = 11.8

EF = 21.5

• Of the two paths to event 3:• Activity A = 2.3 Days• Activity B (+ Dummy) = 11.8 Days

• The longest will become that event’s (Event 3) EF and ES

• We Can now recalculate our EF and time ES as:

EF = ST + E(T) = 11.8 + 9.7 = 21.5 Days

11.8

ES = 0

1

2

A

15.2

4

C

32.3

B

0

EF = 11.8ES = 11.8

EF = 15.2ES = 15.2

ES = 11.8

ES = 21.5


PERT

5 9.7

D

• We can now add on Activity E (Set-up Furniture):

EF = 11.8

EF = 21.5

2.3

ES = 0

1

2

B

15.2

4

C

311.8

A

0

EF = 2.3ES = 2.3

EF = 15.2ES = 15.2

ES = 11.8

ES = 21.5

(NOTE: We’ve swapped Activities A and B to make the diagram clearer)

6

E

2.0

EF = 13.8ES = 13.8

Activity E can start at event 3 (time 11.8), is expected to take 2.0 days to complete, will be completed at event 6, implying: EF = ST + E(T) = 11.8 + 2.0 = 13.8 Days


PERT

5 9.7

D

EF = 11.8

EF = 21.5

2.3

ES = 0

1

2

B

15.2

4

C

311.8

A

0

EF = 2.3ES = 2.3

EF = 15.2ES = 15.2

ES = 11.8

ES = 21.5

6

E

2.0

EF = 13.8ES = 13.8

• We can now add on Activity F (Hire and Train Staff):

7F

4.2

Activity F can start at event 4 (time 15.2), is expected to take 4.2 days to complete, will be completed at event 7, implying: EF = ST + E(T) = 15.2 + 4.2 = 19.4 Days

EF = 19.4ES = 19.4


PERT

5 9.7

D

EF = 11.8

EF = 21.5

2.3

ES = 0

1

2

B

15.2

4

C

311.8

A

0

EF = 2.3ES = 2.3

EF = 15.2ES = 15.2

ES = 11.8

ES = 21.5

6

E

2.0

EF = 13.8ES = 13.8

7F

4.2EF = 19.4ES = 19.4

Wait!!! Where will the Last Activity (Activity G) Start ?? Event 5, 6, or 7 ??? • We know that

Activity G (Move In) can occur only after all three precedent activities (D, E, and F) have been completed

• We also know that an activity can begin with only event

??? SO ???• We need to redraw

our diagram to reflect these conditions


PERT

5 9.7

D

EF = 11.8

EF = 21.5

2.3

ES = 0

1

2

B

15.2

4

C

311.8

A

0

EF = 2.3ES = 2.3

EF = 15.2ES = 15.2

ES = 11.8

ES = 21.5

6

E

2.0

EF = 13.8ES = 13.8

F4.2

EF = 21.5ES = 21.5

• Since all activities must end at a common event: • We need to determine the EF times for event 5 (equal to the longest

paths to it):

Activity ES(6) + Dummy = 13.8 + 0

= 13.6 Days

Activity ES(4) + F = 15.2 + 4.2 = 20.4 Days

Activity ES(3) + D = 11.8 +9.7 = 21.5 Days


PERT

5 9.7

D

EF = 11.8

EF = 21.5

2.3

ES = 0

1

2

B

15.2

4

C

311.8

A

0

EF = 2.3ES = 2.3

EF = 15.2ES = 15.2

ES = 11.8

ES = 21.5

6

E

2.0

EF = 13.8ES = 13.8

F4.2

EF = 21.5ES = 21.5

• Now all we need to do is add in the final activity (Move In):

6 1.2

G

EF = ST + E(T) = 21.5 + 1.2 = 22.7 Days

EF = 22.7

Our Gantt Chart Estimates weren’t too

bad!!!


Is there anyway to save time ???• Maybe• IF we knew which activities were critical, we could focus on

those and either try to reduce the time necessary or make sure they were met

How ???• We could increase the resources necessary to perform those

activities

• We could shift resources from non-critical activities to the critical ones

The approach is called the Critical Path Method (CPM)


CPM• CPM is mainly an attempt to assure that we can finish on

time (Finishing early is gravy)

• The idea is that if we work backwards from the end of the project, we can determine: • The Latest Finishing (LF) times for an event

• The latest time we can finish an activity and still be on time

• Which activities are critical • Activities which if delayed will delay the entire project

• Which activities are Not critical • Non-critical activities have ‘time-to-spare’, or slack time

associated with them• Slack = LS – ES

• The Latest Starting (LS) times for an event • The latest time we can start an activity and still be on time • LS = LF – E(T)


PERT

• Let’s start at the end of the PERT diagram and work back:• Obviously, the latest we want to finish (LF) the project is at day 22.7

So the event is CRITICAL(It MUST be completed on Time)

Slack = 0.0

• That means our Latest Start (LS) time for Activity G would be: LS = LF – E(T) = 22.7 – 1.2 = 21.5

LS = 21.5

• That means our Slack time for Activity G would be: Slack = LS – ES = 21.5 – 21.5 = 0

6 1.2

G

EF = 22.7

5


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• The Next event has multiple activities which are ended by it, so we need to consider each one individually:

The LS time for the activity is:LS = LF - E(T) = 21.5 – 0 = 21.5

LS = 21.5

Our Slack time is:Slack = LS – ES = 21.5 – 13.8 = 7.7

Slack = 7.7

So the event is NOT Critical(We could delay starting the Dummy Activity for up to 7.7 Days and

Still complete the project on time)


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Looking at Activity E (Set-up Furniture):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8

The LS time for the activity is:

LS = LF - E(T) = 21.5 –2.0 = 19.5

LS = 19.5

That means our Slack time for the activity E is:

Slack = LS – ES = 19.5 – 11.8 = 5.7

Slack = 7.7

The event is NOT Critical(We could delay starting the Activity E for up to 7.7 Days

and Still complete the project on time)


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Looking at Activity D (Remodel and Install Phones):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8

The LS time for the activity is:LS = LF - E(T) = 21.5 – 9.7 = 11.8

LS = 19.5


Slack = 7.7

The event is Critical

9.7

D EF = 21.5

ES = 21.5

LS = 11.8 Slack = 0.0


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Looking at Activity F (Hire and Train Staff):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8

The LS time for the activity is:LS = LF - E(T) = 21.5 – 4.2 = 17.3

LS = 19.5


Slack = 7.7

9.7

D EF = 21.5

ES = 21.5

LS = 11.8 Slack = 0.0

4EF = 15.2ES = 15.2

F4.2

LS = 17.3 Slack = 2.1

The event is NOT Critical(We could delay starting the Activity F for up to 2.1 Days

and Still complete the project on time)


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Looking at Dummy Activity (Again):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8

The LS time for the activity is: LS = LF - E(T) = 11.8 – 0.0 = 11.8

LS = 19.5


Slack = 7.7

9.7

D EF = 21.5

ES = 21.5

LS = 11.8 Slack = 0.0

4EF = 15.2ES = 15.2

F4.2

LS = 11.8

Slack = 2.1

The event is NOT Critical(We could delay starting the

Dummy Activity for up to 9.5 Days and Still complete the

project on time)

2

EF = 2.3ES = 2.3

0

LS = 17.3

Slack = 9.5


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Looking at Activity B (Select and Order Office Furniture):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8


LS = 19.5


Slack = 7.7

9.7

D EF = 21.5

ES = 21.5

LS = 11.8 Slack = 0.0

4EF = 15.2ES = 15.2

F4.2

LS = 11.8

Slack = 2.1



project on time)

2

EF = 2.3ES = 2.3

0

LS = 17.3

Slack = 9.5

2.3

1

B

ES = 0

LS = 9.5 Slack = 9.5


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Looking at Activity B (Select and Order Office Furniture):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8


LS = 19.5


Slack = 7.7

9.7

D EF = 21.5

ES = 21.5

LS = 11.8 Slack = 0.0

4EF = 15.2ES = 15.2

F4.2

Slack = 2.1



project on time)

2

EF = 2.3ES = 2.3

0

LS = 17.3

2.3

1

B

ES = 0

LS = 9.5 Slack = 9.5

15.2C

LS = 2.1

Slack = 2.1

LS = 11.8 Slack = 9.5


PERT

Slack = 0.0 LS = 21.5

6 1.2

G

EF = 22.7

5

EF = 13.8ES = 13.8

0

6

• Finally, Looking at Activity A (Locate Office):

LS = 21.5 Slack = 7.7

E

2.0

3EF = 11.8ES = 11.8


LS = 19.5


Slack = 7.7

9.7

D EF = 21.5

ES = 21.5

LS = 11.8 Slack = 0.0

4EF = 15.2ES = 15.2

F4.2

Slack = 2.1

The event is CRITICAL

2

EF = 2.3ES = 2.3

0

LS = 17.3

2.3

1

B

ES = 0

LS = 9.5 Slack = 9.5

15.2C

LS = 2.1

Slack = 2.14

11.8A

EF = 15.2ES = 15.2

LS = 0.1

Slack = 0

LS = 11.8 Slack = 9.5


CPM

• IF we do not perform the critical activities on time, the project will be delayed

So?? What does that mean ???

• Activity A: Locate an Office• Activity D: Remodel and Install phones• Activity G: Move In

• It also indicates where we might want to Allocate additional Resources• If, for example, Manny was assigned to look for an office on his

own, while Mo and Jack were to interview potential staff members, maybe it would be better if Manny and Mo looked for an office (separately), while Jack did all of the Interviewing

How would we know if that would save us time ???• We would have to go back and re-estimate all of our times,

and then redo our PERT/CPM Network


CPM

But our estimates are just that! What’s the likelihood that we will finish on time?• Because we specified the optimistic and pessimistic times for

each activity, we can calculate the variance (or Standard Deviation) in time to perform an Activity.

Optimistic Time – Pessimistic Time

6=

b – a

6• For our critical path, the standard Deviation is:

=

4.33 DaysTotal:

= 0.17 Days2 Day1 DaysG

= 0.83 Days3 Weeks2 WeeksD

= 3.33 Days6 weeks2 WeeksA

baActivity

30 – 106

15 – 106

2 – 16

• In this case, the Standard Deviation ( Variance = ) as:


CPM

So?? What does that mean??• Given that we now know:

• We can calculate the probability of completing the project on time as:

Expected Time – Average Time

Standard Deviation=

22.7 – 21

4.33

• Without going into detail, if we were to look at the area under a standardized normal curve for a z of 0.39, we would find:

=z

• The total Average time to complete the activities• The total Expected time to complete the activities• The total Standard Deviation of the path

= 0.39

What is this, a joke ????

We have a 65% chance of completing the Project on Time


Project Management Software

• Fortunately, because project management is a large part of any software development, and because projects can quickly become very complicated, there are a number of Project Management Software Packages Available:• Result’s Management Suite• Project Workbench• C-A Super Project• Project Scheduler• Microsoft Project


Microsoft Project Gantt Chart


Microsoft Project PERT Chart


Entering Intertask Dependencies Microsoft Project


Entering Schedule in Calendar View:


Defining Project Resources:


Assigning Project Resources:


Progress Reporting on a Gantt Chart:


????????????? Any Questions

(Please !!!) ?????????????

MIT5312: Professor KirsProject Management Slide 1 An Overview of Project Management Chapter 4 of the...

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