1. Methods and Work Measurement
Lecture 4:
The General Problem Solving Process
6 March 2009

2. Systematic Procedures for “work measurement and ergonomy”
Identify problem
Collect data
Analyze data
Develop alternative solutions
Select a solution
Install solution
Follow up
Hanna Lestari, ST, M.Eng-FTI-UII

3. Problem Identification
Tools:
-Pareto analysis
- Fishbone diagram
- Gantt chart
- PERT charting
Examples:
Product with low profit
Bottleneck operations
Workers complaints
Hanna Lestari, ST, M.Eng-FTI-UII

4. Recording Tools Operation Process Chart (OPC) Flow Process Chart
Flow Diagram
Gang Process Charts
Worker and Machine Process Charts
The Two-hand Process Chart
Hanna Lestari, ST, M.Eng-FTI-UII

5. Analysis Tools 5 Why 4W + 1H Why is this operation necessary?
Why is this operation performed in this manner? …
4W + 1H
How can the operation be performed better?
Who can best perform the operation?
Where could …
When …
Why …
Hanna Lestari, ST, M.Eng-FTI-UII

6. 7 Tools Check sheets Histograms Pareto diagrams
Cause and effect diagrams
Stratification
Scatter diagrams
SPC
Hanna Lestari, ST, M.Eng-FTI-UII

7. 7 Waste Waste from overproduction Waste from waiting times
Waste from transportation and handling
Waste related to useless and excess inventories
Waste in production process
Useless motions
Waste from scrap and defects
Hanna Lestari, ST, M.Eng-FTI-UII

8. The General Problem-solving Process
Function of
Organization
Decision Making
Process
8 Steps of Problem Solving
Determining the priority
of problem
Problem
Identification
Plan
2. Finding causes of
problem
3. Investigate the most
important/main causes
4. Determining the steps
of improvement
2. Developing Alternatives
Solution Do
3. Selecting Alternative
5. Do the steps
4. Implementation
Check
5. Evaluation
6. Evaluating the result
of improvement
7. Preventing the problem
occur again
Action
8. Solve the next problems
Hanna Lestari, ST, M.Eng-FTI-UII

9. Problem-Solving Tool Kit
Hanna Lestari, ST, M.Eng-FTI-UII

10. Problem-Solving Tools
Problem-Solving Tools is called by seven quality control tools. They are:
1. Check sheet
2. Histogram
3. Pareto diagram
4. Fish diagram (the cause-effect diagram)
5. Stratification
6. Scatter diagram
7. Statistical Process Control (SPC)
Hanna Lestari, ST, M.Eng-FTI-UII

11. Check Sheets
Check sheet is a simple tool for collecting data so that the errors that probably occurred can be avoided.
Hanna Lestari, ST, M.Eng-FTI-UII

12. Checksheets Purpose: Benefits:
Tool for collecting and organizing measured or counted data
Data collected can be used as input data for other quality tools
Benefits:
Collect data in a systematic and organized manner
To determine source of problem
To facilitate classification of data (stratification)
In the top chart we see two operators and two machines. In the morning both operators and both machines seem to be working well. However in the afternoon we see both operators are more prone to defects and the machine two is very prone to problems. We conclude there may be some operator fatigue involved AND that there is some condition on machine two that needs to be investigated. Look for something that affects on machine but not the other like sun glare…
Conditions
Workers
Material
Hanna Lestari, ST, M.Eng-FTI-UII

13. Histogram
This tool is to function as describing a distribution type of data.
Hanna Lestari, ST, M.Eng-FTI-UII

14. Histograms Purpose: How is it done?:
To determine the spread or variation of a set of data points in a graphical form
How is it done?:
Collect data, data point
Determine the range of the data
Calculate the size of the class interval
Divide data points into classes Determine the class boundary
Count # of data points in each class
Draw the histogram
Displays distributions
Remember the bell curve from school… a few Fs many Bs and Cs a few As.
Stable process, exhibiting bell shape
Hanna Lestari, ST, M.Eng-FTI-UII

15. Pareto Diagram
Problem areas can be defined by a technique developed by the economist Vilfredo Pareto to explain the concentration of wealth. In Pareto analysis, items of interest are identified and measured on a common scale and are then ordered in ascending order, creating a cumulative distribution
Hanna Lestari, ST, M.Eng-FTI-UII

16. Pareto Diagram Purpose: How is it done? Prioritize problems.
Create a preliminary list of problem classifications.
Tally the occurrences in each problem classification.
Arrange each classification in order from highest to lowest
Construct the bar chart
Column graph in rank order
80% of problems related by 20% of causes
The vital few and the trivial many – Dr. Juran
Identifies problems to be worked first
Hanna Lestari, ST, M.Eng-FTI-UII

17. Pareto Diagram Benefits:
Pareto analysis helps graphically display results so the significant few problems emerge from the general background
It tells you what to work on first
Conclusion:
We need to concentrate on dents
Its good that there are not many gaps because they are very expensive.
TRAP
This works sometimes but another type of chart is frequently better
Hanna Lestari, ST, M.Eng-FTI-UII

18. Pareto Diagram Weighted Pareto
Pareto Charts
Weighted Pareto
Weighted Pareto charts use the quantity of defects multiplied by their cost to determine the order.
Defects times cost
Gap becomes the obvious place to start corrective actions
Costs more than all others put together!!!
Hanna Lestari, ST, M.Eng-FTI-UII

19. Fishbone Diagram
Also known as ishikawa or cause-effect diagram. Fish diagrams were developed by Ishikawa in the early 1950s
No statistics involved
Maps out a process/problem
Makes improvement easier
Looks like a “Fish Skeleton”
Hanna Lestari, ST, M.Eng-FTI-UII

20. Fishbone Diagram
Hanna Lestari, ST, M.Eng-FTI-UII

21. Constructing a Fishbone Diagram
Step 1 - Identify the Problem
Step 2 - Draw “spine” and “bones”
Example: High Inventory Shrinkage at local Drug Stor
For the example Diagram, inventory shrinkage was used. This is a measure of the shoplifted, stolen, or broken goods at a store.
This is placed in a rectangle at the “head” of the fish.
Shrinkage
Hanna Lestari, ST, M.Eng-FTI-UII

22. Constructing a Fishbone Diagram
Step 3 - Identify different areas where problems may arise from
Ex. : High Inventory Shrinkage at local Drug Store
employees
Here “employees” and “shoplifters” were used as categories that problems may have come from. In other examples, it is acceptable to use Machines, Materials, Methods, and People as general categories(These are from Foster, see bibliography). These should encompass all aspects of the business.
Shrinkage
shoplifters
Hanna Lestari, ST, M.Eng-FTI-UII

23. Constructing a Fishbone Diagram
Step 4 - Identify what these specific causes could be
Ex. : High Inventory Shrinkage at local Drug Store
The brainstorming process should continue until every angle is covered. Keeping asking for examples until no more exist. According to Foster, 5 causes should be enough for most categories.
Shrinkage
Anti-theft tags poorly designed
Expensive merchandise out in the open
No security/ surveillance
shoplifters
Hanna Lestari, ST, M.Eng-FTI-UII

24. Constructing a Fishbone Diagram
Ex. : High Inventory Shrinkage at local Drug Store
employees
attitude
training
new trainee
benefits
practices
With the completion of the diagram, several points have been made about inventory shrinkage’s possible sources. These may or may not have been obvious to management before this brainstorming process occurred.
Shrinkage
Anti-theft tags poorly designed
Expensive merchandise out in the open
No security/ surveillance
shoplifters
Hanna Lestari, ST, M.Eng-FTI-UII

25. Constructing a Fishbone Diagram
Step 5 – Use the finished diagram to brainstorm solutions to the main problems.
At this time, you can go back to the previous slide and brainstorm with the class about solutions to these problems, or other causes. This is the utility of the Cause-and-Effect Diagram.
Moving expensive merchandise behind the counters and educating employees to their perks may be some solutions to this problem.
Hanna Lestari, ST, M.Eng-FTI-UII

26. Stratification
Stratification is a effort for grouping data into several groups that have the similar characteristics
Use in combo with other tools
Separates data to view patterns
Use before collecting data
Improves estimation
Analyze subsets
Hanna Lestari, ST, M.Eng-FTI-UII

27. Scatter Diagrams Purpose:
To identify the correlations that might exist between a quality characteristic and a factor that might be driving it
A scatter diagram shows the correlation between two variables in a process.
These variables could be a Critical To Quality (CTQ) characteristic and a factor affecting it two factors affecting a CTQ or two related quality characteristics.
Dots representing data points are scattered on the diagram.
The extent to which the dots cluster together in a line across the diagram shows the strength with which the two factors are related.
Shows relationship between two variables
Hanna Lestari, ST, M.Eng-FTI-UII

28. Scatter Diagrams How is it done?:
Decide which paired factors you want to examine. Both factors must be measurable on some incremental linear scale.
Collect 30 to 100 paired data points.
Find the highest and lowest value for both variables.
Draw the vertical (y) and horizontal (x) axes of a graph.
Plot the data
Title the diagram
The shape that the cluster of dots takes will tell you something about the relationship between the two variables that you tested.
Hanna Lestari, ST, M.Eng-FTI-UII

29. If the variables are correlated, when one changes the other probably also changes.
Dots that look like they are trying to form a line are strongly correlated.
Sometimes the scatter plot may show little correlation when all the data are considered at once.
Stratifying the data, that is, breaking it into two or more groups based on some difference such as the equipment used, the time of day, some variation in materials or differences in the people involved, may show surprising results
Scatter Diagrams
Hanna Lestari, ST, M.Eng-FTI-UII

30. Scatter Diagrams
You may occasionally get scatter diagrams that look boomerang- or banana-shaped.
To analyze the strength of the correlation, divide the scatter plot into two sections.
Treat each half separately in your analysis
Benefits:
Helps identify and test probable causes.
By knowing which elements of your process are related and how they are related, you will know what to control or what to vary to affect a quality characteristic.
To control variation in any process -it is absolutely essential that you understand which causes are generating which effects.
Hanna Lestari, ST, M.Eng-FTI-UII

31. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

32. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

33. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

34. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

35. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

36. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

37. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

38. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

39. Statistical Process Control
Hanna Lestari, ST, M.Eng-FTI-UII

40. The General Problem-solving Process
In fact, the five steps described here are useful in the logical and systematic approach to solving almost any problem.
1. Problem Definition.
The definition or formulation of the problem is the first step in the problem-solving procedure, this is often preceded by the need to recognize that a problem exists such as,
"Costs are too high,"
"Output must be increased," or
"There is a bottleneck in order filling in the warehouse. "

41. The General Problem-solving Process(02)
2. Analysis of the Problem.
The formulation of the problem may have resulted in a broad statement or definition. Now it becomes necessary to obtain data to sort out the facts and determine how they apply to the problem
3. Search for Possible Solutions.
The basic objective of course is to find the preferred solution that will meet the criteria and the specifications that have been establish. This suggests that several alternative solutions be found and then the preferred solution can be selected from these.

42. The General Problem-solving Process(03)
4. Evaluation of Alternatives.
We have now arrived at several solutions or par­tial solutions to the problem under consideration. In fact, we may have accumulated a large number of ideas bearing on the problem. Some of these can be eliminated rather quickly and the remaining solutions can be considered more carefully. An examina­tion can be made to determine to what extent each solution meets the criteria and conforms to the original specifications
5. Recommendation for Action.
In many cases, the person who solves the problem is not the one who will either use the recommended solution or give final ap­proval for its adoption. Therefore, after the preferred solution has been found, it must be communicated to other persons. The most common form of communication of course is the written or oral report. The written report or the oral presentation then becomes the final step in the problem-solving procedure

43. Hanna Lestari, ST, M.Eng-FTI-UII