Algorithms and Problem Solving-1 Algorithms and Problem Solving.
Problem Solving
description
Transcript of Problem Solving
Problem Solving
An interactive self training program
The illiterate of the 21st century will not be those
who cannot read & write,
but those who cannot learn, unlearn and relearn
- Alvin Toffler
Goals: 1. To provide an understanding of problem solving, as a process and a
revolution in thought2. To provide an understanding of what to analyse and how to use
analytical tools.3. Suggest a few steps that could be used for problem solving. Adopt a
systematic approach
Desired outcome:
a) Be aware that there exists a scientific system of taking decisions which may challenge many of our present ways
b) Develop conviction that analysis helps problem solvingc) Acquire the desire to start implementing a process orientation in
problem solving in one’s own department d) Answer how organisations can transform themselves and become
world class
Problem Solving
Why learn Problem Solving
• To develop a systematic approach Learn possible frameworks for understand & resolving problems Be able to reflect and analyse the approach Learning to improve problem solving skills Transfer skills, knowledge and experience to new problems Create a knowledge repository /avoid eyelash effect Logical and rational approach
• See problems in a new way• Develop interpersonal skills and personal qualities• Improve success rate
How we do problem solving
Facts / data available
Facts / data selected
Inferences made
Judgments made
Decisions made
Actionstaken
Common methodologies of problem solving
• Intuition
• Judgment
• Ostrich Approach
• Trial and error
• Try the first solution
• Ask advice
• Delegate upwards or downwards
The path to skill in decision making
Unconsciousincompetence
Consciousincompetence
Consciouscompetence
Unconsciouscompetence
Rules of thumb recipes
Myriad specific situations
Problem solving terminology
PURPOSE
Problem
ISSUE
SolutionCause
Solvable Cause
Problem Solving setting
Creativity
Self Development
Total Quality Management
Change Management
Negotiation
Innovation
Problem Solving
Thinking Patterns for judgments
• Strategic thinking• Emotional thinking• Realistic thinking
– What we can do– Fix the essential problems first– Paretto analysis (draw)
• Empirical thinking– Past experience– Available Data base– Done before
• Rational thinking– Set ideal situation ‘To be”– Identify ‘as is’– Identify gaps - problems– Break own problems to causes– Choose reasonable alternatives– Implement solutions
• Systems thinking (more scientific)– Purpose– Input– Output– Function– Inside cause (solvable)– Outside cause (unsolvable)– Result
Thinking Patterns for systematic thinking
Thinking Patterns for systematic thinking
• Cause & Effect thinking– Fish Bone– Tree diagrams
• Contingent thinking– Game Theory
• Different Situations• Analysis• Solution for each situation
• Why – Why analysis
Thinking Patterns for efficient thinking
• Hypothesis thinking– Develop hypothesis based on available information– Collect information to prove hypothesis– Test hypothesis against information, if OK proceed, if not – develop new
hypothesis• Conception thinking
– When you need creativity and flexibility– New Product Development – Shoji – Shiba or Triz methodolgy– Be visual– Write down what you think– Use cards, draw, write, arrange ideas– Change positions, group, form, viewpoints– After creating ideas translate into explanations
Thinking Patterns for efficient thinking
• Structure thinking– Tree diagrams– Affinity diagrams
• Convergence & Divergence thinking– Creative ideas – divergence– Summarize - convergence
• Time order thinking– Prioritization
Problem Solving&
Decision Making
Challenges
Goals
Opportunities
Suitable
Feasible
Flexible
Define the Problem
Gather Information
DevelopAlternatives
WeighAlternatives
Facts & Data Boundaries
Stakeholders Opinions &Assumptions
Brainstorm
Openness
Identify importantCriteria
Identify advantages& constraintsSelect the
alternativeImplement
Solution
Develop a planInform
stakeholdersCompromise
ResultsProcedure &
ProcessMonitorProgress
Review/Learn from your
Experience
Evaluate &
Prioritize
If results do not meet
expectations
reconsider
Data analysis
Standardize
PROBLEM SOLVING
What is a problem
• Are issues ------- problems• Are causes -------- problems
A problem is the undesirable result of a job Takahashi & Kume
A problem is a gap between the actual state of affairs and goals, or the way things should be
JUSE Problem Solving Research Group
WHAT IS A PROBLEM?
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Time
1. Maintenance Related• Deals with abnormalities• Find and removes cause so as to
prevent problem from recurring• Bring process back to status quo
Processabnormality
Level
• Change level (eg. Reduce defective rate, increase production quantity, error rate, improve percentage on-time delivery), or• Reduce variation (make the process more capable)• Or both, ie, change level and reduce variation• Causes process to become better, cheaper, faster, safer, easier etc.
WHAT IS A PROBLEM?2. Improvement Related
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A
C
Sponsor & Team
Reflection Reflecting and looking into the future
PROBLEM SOLVING PROCESSSponsor/Management/Voluntary Group
TeamPlanning
A. Understanding problem areas
B. Selecting the theme
C. Forming the team
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Team
The ProblemSolvingProcess
1. Understanding current circumstances
2. Establishing activity plan & targets
3. Analysing the causes
4. Researching the improvement plan
5. Implement the plan
6. Verifying the results
7. Standardising & institutionalising
PROBLEM-SOLVING LEVELSI. Input based:
(Not part of problem-solving)
1. 5-S activities
2. Abnormality tags on equipmentWhy-why analysis
II.
Output based:Part of problem-solving
1. Abnormality.(sporadic) : Corrective Action
P-M Analysis Statistical tools
Statistical toolsManagement tools DOE
2. Stable/chronic trouble : Corrective Action
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PROBLEM-SOLVING LEVELS
II.
Output based:Part of problem-solving (Contd.)
3. Early stage instability : Corrective Action
4. Improvement (of Q, C, D, S, M)
Statistical toolsDOE
Statistical toolsLanguage toolsDOE
DOEFMEA/FTAPDPC
5. Task Achievement type.
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TOOLS
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QC techniques are methods for establishing control by discovering problems, arranging and interpreting information, analysing factors, taking corrective actions, and making improvements K. Hosotani
TOOLS
1. Check sheet2. Pareto diagram3. Cause-and-effect diagram4. Histogram5. Control chart6. Scatter diagram7. Graph
1. Relations diagram2. Affinity diagram3. Matrix diagram4. Systematic diagram(Tree diagram)5. Matrix data analysis6. Process Decision Program Chart (PDPC)7. Arrow diagram
Seven Management ToolsSeven QC Tools
• Flowcharts• Sampling methods• Testing and estimation• Design of experiments
• Correlation and regression analysis• Reliability engineering (FTA,FMEA,Weibull..)• Multivariate analysis• Optimisation methods (Linear Programming etc)
Other tools
WORKING WITH FACTS AND DATA• Being reality oriented, not just concept oriented
The Three Reals
1. The real workplace2. The real object3. The real fact
• Distinction between facts and opinions (or interpretation). Use of language tools
• Precise use of language is related to thinking with facts
• Where there are a number of complex interrelations between causes statistical treatment is essential
WORKING WITH FACTS AND DATA - 1PURPOSES OF DATA
1. Data to assist in understanding the actual situation Arrange data for easy understanding, estimations or comparisons
2. Data for analysis: Analytical data examines the relationships between an effect and its causes
3. Data for control: Data to determine whether or not a process is normal, i.e. under control
4. Acceptance or rejection data: Data used to approve or reject, through total or sampling inspection
5. Regulating data Example : for raising an oven temperature
6. Data for records: QA records for product liability or Excise records
WORKING WITH FACTS AND DATA - 2PURPOSES OF DATA
To take corrective action it is essential to have a constant, accurate Grasp of the facts. When we go out and collect data, it becomes clear that our vague guesses based on experience were way off the mark. Checking the facts enables us to bring in effective countermeasures, leading to good results. K. Hosotani
VARIATION - TYPES OF CAUSESTwo types of causes causing variation
Variation which occurs due to an abnormality in the process and results in a particularly large variation
Occurs when work standards are not correct, or are not obeyed, or are not there at all, or people operate in different ways. Also when there are specific reasons like changes in tools, materials etc. Problems are sporadic
Called :Special causesAssignable causes
Special causes
Variation which occurs even when the process is being operated the same way as always
This variation is a part of the system. Problems are chronic. To reduce this, the method (process) or system must be changed. This is the management’s responsibility
Called :Random causesChance causesCommon causes
Common causes
DATADISPERSION
Process out-of-controlThe out-of-control point has in all likelihood a special cause which must be identified and removed.
Questions to ask: What was different? What has changed? Looking at all the points together will not help.
Was the standard followed? Was anything different observed about man, machine, material or method?
Is there a known special cause such as power failure?
Common CauseWhen variation occurs due to common causes only, the process is stable or in control
Process in control“In control” is a statistical term. It does not necessarily mean the variability is acceptable. In fact, most problems arise from processes in control which are outside desired limits. Whose responsibility is this? Management’s or workers’?
A process in control is predictable, that is, it will vary randomly within a range (with exceptions).
No one point has any special meaning
Special CauseWhen variation occurs due to special causes, the process is unstable or is out of control
FUNNEL EXPERIMENT -2 (From Deming and Joiner)
• When a stable process is adjusted for an undesirable (or extra good) result, the variation will be worse than if the process were left alone
• In the above marble and funnel example, the goal is to drop the marble on a target spot
• Consider four rules:
Rule 1 : Leave funnel fixed, aimed at target, no adjustmentRule 2 : At drop k (k = 1,2,3,…) the marble rests at point z, measured from
the target. Move funnel the distance “minus z k” from its last position.
Memory 1Rule 3 : Set the funnel over point “minus z k” measured from target. No memoryRule 4 : Set funnel at each drop right over z k where it last came to rest. No memory What results ?
FUNNEL EXPERIMENT - 1 (From Deming and Joiner)
Record of drops of the marble through the funnel under the four rules described in the text. Rule 1, Rule 2, Rule 3, Rule 4. Only far-off points are shown, to avoid congestion.
THE FOUR WORK HABITS
Rule 1
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Rule 2
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The result of the four rules:
FUNNEL EXPERIMENT - 3OVERADJUSTMENT
Rule 3
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Each rule appeared logical. But the results in a stable system areachieved when there is no tampering. Rule 2 caused an increasein variation (the control limits are widened by 41%). Rule 3 causeswild bouncing in both directions. Rule 4 is like “taking a randomwalk, off to the milky way”
Rule 4
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Each rule appeared logical. But the results in a stable system areachieved when there is no tampering. Rule 2 caused an increasein variation (the control limits are widened by 41%). Rule 3 causeswild bouncing in both directions. Rule 4 is like “taking a randomwalk, off to the milky way”
Rule 4
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The result of the four rules:
FUNNEL EXPERIMENT - 4OVERADJUSTMENT
ACTION ON CAUSESThree levels of actions on problems:
1. Correction: Action to eliminate a detected nonconformity. (ISO 9000) i.e., acting on symptoms or phenomena e.g., rework, regrade, sort, replace
2. Corrective Action: Action to eliminate the cause of a detected nonconformity or other undesirable situation. (ISO 9000)
3. Preventive Action: Action to eliminate the cause of a potential nonconformity or other considerable situation i.e., preventing the occurrence of a problem before it arises
1. Problem: We periodically get defective supplies of this plunger due to bend.
We have asked the vendor many times to improve Solution: We are developing another vendor 2. Problem : Customer X has got a delivery mixed up with products meant for customer Y Solution: Train the stores staff (Does this necessarily mean
corrective action?)3. Problem: We got a customer complaint that the bore was oversize Solution: We are now inspecting the bore 100% (Correction/Corrective Action/Preventive Action?)4. Problem : Customer A has complained once again of defect type
T in our fabric
Solution: Production Dept. should be more vigilant (What type of action?)
ACTION ON CAUSESACTING ON SYMPTOMS - ACTUAL EXAMPLES
PRIORITISATION
Continued
A B C D
Vital few
Useful many Prioritise problems, causes andopportunities for improvement
1. Choice of defect types or causes to eliminate, or markets (or products) to develop, potential equipment errors to correct, or cost improvements to be effected where inter-dependence between choices is low.
Tools: Pareto diagram, FMEA, circling items in a cause-and-effect diagram, mapping desired vs current product profile in QFD, resource allocation or production sequencing algorithms
PRIORITISATION
2. Choice of key issues or problems to address, as in policy management, i.e. we get leverage. The issues are strongly interdependent.
Address the core issue, solving which many symptoms or potential troubles are eliminated, at one go.
Tools: JIT methods (pacemaker process) Fault-tree analysis, PDPC. TOC tools: Current and future reality trees, Prerequisite trees
Consensus tools also help focus on key issues.
EXAMPLE
FMEA of Monthly production plan
PROCESS ORIENTATION
• Without an output or a result, no process can be said to exist. To improve any result, we have to improve the inputs and factors.
Process Orientation
Focus on outcome alone. Ends justify means.Believe that “somehow” results can be delivered.
Ends and means are not separable. We cannot control the result, only the means. A result cannot be improved on its own.
Short-term thinking, often at the expense of what is more important, or at the expense of another result area. Distorted measurements and goals.
Focus on lasting results, strong fundamentals, evenat the expense of short term difficulty. Measurements & goals reflect real stakeholder needs.
“Man control”. Like inspection, deals with results, after the fact. Numerical goals, quotas.
Fact control. Deals with factors, and strengthens them.
Forces people to “window-dress” results. Promotes openness to reality.Emphasis on control, rewards and punishment,extrinsic motivators, attachment to results.
Emphasis on commitment, intrinsic motivation.
MBO ! TQM
Result Orientation
Inputs
Factors Result
= Process (Collection of causes producing a result)
• Deming’s visit in 1950 : The wheel of quality control showed QC as an endless cycle of improvement• The “Management” cycle or “Kanri” cycle is an offshoot of this
PDCA CYCLE
DESIGN(PLAN)
MANUFACTU-RING (DO)
RESEARCH&
SERVICE(ACT)
SALES(CHECK)
Continued
PLAN : Define the problem, or state a goal. Determine the method (or process) by which the goal is to be achieved
DO : Train, communicate, execute with everyone’s cooperation
CHECK : Check the results. Check the factors affecting the results. Also check the effects (the impact)
ACT : If results are not OK, take countermeasures on the causes of troubles in planning or in implementation
If results are OK, standardise
PDCA CYCLE
PDCA CYCLEPLAN
A PDC
• The first step in planning is to define the problem or to set goals. Then, the questions must be answered : Why solve this problem ? Why achieve this goal ?
Plan implementation
Define problem, set goals
Understand currentcircumstancesAnalyse the factorsFind solutionsA
C D
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• Having set goals, the method of achieving it has to be determined.
PDCA CYCLEDO
A P
DC
• First Step
1. Train or all people involved2. Communicate with
Detailed standards help in training and communication
• Elements of successful implementation1. Plan adequate resources (manpower, materials, money etc.)2. Get everybody’s cooperation and commitment in advance3. Design detailed activity schedule. Don’t make it too tight but base it on good understanding of what is involved4. Be committed to the task and work to the schedule 5. Pay meticulous attention to detail 6. Correct small things going wrong early, not allowing them them to grow big
PDCA CYCLECHECK
A PDC
CHECK POINTS
(Reflect effectsor results)
INPUTS
PROCESS
RESULTS
CHECK POINTS (Reflect processes or causes)
Continued
PDCA CYCLEACT
A PDC
Result
Take countermeasures on plan or implementation andrecheck
Standardiseor
Maintain as is
OK
Not OK
Continued
PARTICIPATION BY ALL
• Participation means involvement by all in decision making and improvement activities. It means more power to people. It means openness.
Company character
Humanity,solidarity
Emotion
Intelligence
QC, Scientific attitude, rationalism
Good company
- Hosotani
Towards a smarter organization
• Must improve quality of decision making• Adopt rational decision process• Train appropriate personnel in the tools for decision
making• Improved understanding and implementation through
repeated use. • Six Tools
– Get support from top– Start small, be patient– Demonstrate value of rational decision making– Train people– Don’t be a hammer looking for a nail– Practice continuous improvement
Never be afraid to try something new.
Remember amateurs built the Ark.
Professionals built the TitanicUnknown
Systems Thinking
WHY WHY Analysis
• When confronted with a problem, have you ever stopped & asked why five times ?
• It is difficult to do even though it sounds easy. For example, suppose a machine stopped functioning: Question 1: Why did the machine stop?Answer 1 : Because the fuse blew due to an overloadQuestion 2 : Why was there an overload?Answer 2 : Because the bearing lubrication was inadequateQuestion 3 : Why was the lubrication inadequate?Answer 3 : Because the lubrication pump was not pumping sufficientlyQuestion 4 : Why wasn’t the lubricating pump working right?Answer 4 : Because the pump shaft was worn and rattlingQuestion 5 : Why was it worn out?Answer 5 : Because there was no strainer and the metal scrap got in
• By repeating “why” five times, it was possible to identify the real cause and hence the real solution: attaching a strainer to the lubricating pump.
• If this procedure were not carried through one might as well have replaced the fuse or the pump shaft. In that case, the problem would recur within a few months.