1. Problem Solving Tools 20.10.2017 ILGIN ACAR
ENM 301 WORK STUDY
Problem Solving Tools
ILGIN ACAR

2. Methods engineering
A technique for increasing the production per unit time or decreasing the cost per unit output – productivity improvement
Synonymous terms: Operation analysis, work design, work simplification, corporate engineering
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3. Method engineering steps
Select project (Pareto, Fish diagram, Gantt, PERT)
Get and present data (charts, computations)
Analyze data (operation analysis)
Develop ideal method (motion, work, equipment design)
Present and install method (decision making tools)
Develop job analysis
Establish time standards (time study)
Follow up
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4. Method engineering steps
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5. Method engineering steps
Select project (Pareto, Fish diagram, Gantt, PERT)
Get and present data (charts, computations)
Analyze data (operation analysis)
Develop ideal method (motion, work, equipment design)
Present and install method (decision making tools)
Develop job analysis
Establish time standards (time study)
Follow up
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6. Project selection
The first and perhaps most crucial step is the identification of the problem in a clear and logical form
Typically project selection is based on 3 considerations:
Economic
Technical
Human
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7. Project selection Exploratory tools: Pareto Analysis Fish Diagrams
Gantt Chart
PERT Charting
Job/Worksite Analysis Guide
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8. 1. Pareto analysis
V. Pareto originally observed that in Italy, 80% of the land was owned by 20% of the people
Pareto Principle : 80‐20 Rule (80% of the effects stem from 20% of the causes)
Customer Complaints: 80% of the complaints come from 20% of the customers
Sales: 80% of the profits come from 20% of the products
Quality Management: 80% of the problems come from 20% of the causes
Inventory Management: 80% of the total inventory is found in 20% of the inventory items
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10. 1. Pareto analysis
The aim is to identify the most important factors, defects, or problems
How to draw a Pareto chart?
– Items of interest are identified and measured on a common scale and then ordered in descending order as a cumulative distribution
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11. Step 1 Develop a list of problems, items or causes to be compared.
Step 2 Develop a standard measure for comparing the items.
How often it occurs: frequency (e.g., utilization, complications, errors) How long it takes: time How many resources it uses: cost
 Step 3 Choose a timeframe for collecting the data.
Step 4 Tally, for each item, how often it occurred (or cost or total time it took). Then, add these amounts to determine the grand total for all items. Find the percent of each item in the grand total by taking the sum of the item, dividing it by the grand total and multiplying by 100.
Step 5 List the items being compared in decreasing order of the measure of comparison: e.g., the most frequent to the least frequent. The cumulative percent for an item is the sum of that item’s percent of the total and that of all the other items that come before it in the ordering by rank.

12. Step 6 List the items on the horizontal axis of a graph from highest to lowest. Label the left vertical axis with the numbers (frequency, time or cost), then label the right vertical axis with the cumulative percentages (the cumulative total should equal 100 percent). Draw in the bars for each item.
Step 7 Draw a line graph of the cumulative percentages. The first point on the line graph should line up with the top of the first bar. Excel offers simple charting tools you can use to make your graphs, or you can do them with paper and pencil.
Step 8 Analyze the diagram by identifying those items that appear to account for most of the difficulty. Do this by looking for a clear breakpoint in the line graph, where it starts to level off quickly. If there is not a breakpoint, identify those items that account for 50 percent or more of the effect. If there appears to be no pattern (the bars are essentially all of the same height), think of some factors that may affect the outcome, such as day of week, shift, age group of patients, home village. Then, subdivide the data and draw separate Pareto charts for each subgroup to see if a pattern emerges.

13. 1. Pareto analysis END 202 – Work analysis and design
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18. 1. Pareto analysis Exercise:
Draw a Pareto chart for being late to class .
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19. 2. Fish diagrams Cause‐and‐effect diagrams
Developed by Ishikawa in the early 1950s
Effect: fish head & Causes: fish bones
Principle causes: human, machines, methods, materials, environment, administrative
Provides good overview of a problem and its contributing factors
Aim is to list all possible causes to help to identify potential solutions
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20. 2. Fish diagrams END 202 – Work analysis and design
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21. 2. Fish diagrams Exercise:
Draw a fish diagram for public bus lateness.
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22. 3. Gantt chart
Shows the anticipated completion time for various project activities as bars plotted against time on the horizontal axis
One can determine which project components are ahead or behind schedule
Project‐based or machine‐ or process –based
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23. 3. Gantt chart END 202 – Work analysis and design
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24. 4. PERT Charting Program Evaluation and Review Technique (PERT)
PERT is a model for project management designed to analyze and represent the tasks involved in completing a given project. It is commonly used in conjunction with the critical path method (CPM).
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25. 4. PERT Charting Steps: Determine the events (tasks) and order them
Estimate time for each task (most likely, optimistic, pessimistic)
Find the expected time for each task
Create a network diagram (activity on arrow‐AOA or activity on node‐AON)
Find
The early start time (ES)
The early finish time (EF)
The late start time (LS)
The late finish time (LF)
The slack
Determine the critical path
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26. 4. PERT Charting Example (from Wikipedia): Activity Predecessor
Time estimates
Expected time
Opt. (O)
Normal (M)
Pess. (P) A — 2 4 6
4.00 B 3 5 9
5.33 C 7
5.17 D 10
6.33 E
B, C F 8
4.50 G
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27. 4. PERT Charting Activity on arrow (AOA) network diagram 5 2 6 1 3 4 DF 2 A C 6 1 G B E 3 4
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28. 4. PERT Charting

29. 4. PERT Charting END 202 – Work analysis and design
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31. 4. PERT Charting Advantages of PERT It make the dependencies visible
It allows to identify the critical path
It allows to reduce the project duration with a better understanding
Disadvantages of PERT
With hundreds or thousands of activities difficult to see the dependence
Several pages to print, difficult to read
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32. 5. Job/Worksite analysis guide
Allows to identify the problems within a particular area, department or worksite
The analyst walks in the area, observes the worker, the task, the workplace and the surrounding working environment
The analyst also indentifies any administrative factors that may affect the worker’s behavior or performance
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33. 5. Job/Worksite analysis guide
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