1. Computer Aided Process Planning

2. What is CAPP

3. Process Plan

4. Process Planning

5. Basic Process in developing a process plan

6. Process Planning Approaches
Manual Systems
Computer Aids
Variant System
Experimental Generative System

7. Manually Prepared Process Plans

8. Computer Aids

9. Variant (Retrieval) CAPP Methodology

10. Variant CAPP

11. Variant CAPP

13. Variant CAPP

14. Generative CAPP Methodology

15. Knowledge based process planning

16. Decision Tables
A table of rows and columns, separated into four quadrants
Conditions
Condition alternatives
Actions to be taken
Rules for executing the actions
Kendall & Kendall

17. Figure 9.8 The standard format used for presenting a decision table
A decision table is a table of rows and columns, separated into four quadrants.
The upper left quadrant contains the conditions.
The upper right quadrant contains the condition alternatives.
The lower half of the table contains the actions to be taken on the left and the rules for executing the actions on the right.
When a decision table is used to determine which action needs to be taken, the logic moves clockwise beginning from the upper left.
Kendall & Kendall

18. Developing Decision Tables
Determine conditions that affect the decision
Determine possible actions that can be taken
Determine condition alternatives for each condition
Calculate the maximum number of columns in the decision table
Fill in the condition alternatives
Complete table by inserting an X where rules suggest actions
Combine rules where it is apparent
Check for impossible situations
Rearrange to make more understandable
Determine the number of conditions that affect the decision – the number of conditions becomes the number of rows in the top half of the decision table.
Determine the number of possible actions that can be taken – this becomes the number of rows in the lower half of the decision table.
Determine condition alternatives for each condition – in the simplest form two alternatives (Y or N), in an extended there may be many alternatives.
Calculate the maximum number of columns in the decision table – the product of the number of alternatives for each condition. If there were four conditions and 2 alternatives for each condition, there would be 16 possibilities (2x2x2x2)
Kendall & Kendall

19. Figure 9.10 Constructing a decision table for deciding which catalog to send to customers who order only from selected catalogs
Kendall & Kendall

20. Checking for Completeness and Accuracy
Four main problems
Incompleteness
Impossible situations
Contradictions
Redundancy
Incompleteness –if a condition is left out, the whole decision table would change because a new condition, new set of alternatives, new action, and one or more new action rules would have to be added.
Impossible situations – for example a person can not earn greater than $50,000 per year and less that $2,000 per month.
Contradictions – occur when rules suggest different actions but satisfy the same conditions.
Redundancy – occurs when identical sets of alternatives require the exact same action.
Kendall & Kendall

21. Figure 9.14 Checking the decision table for inadvertent contradictions and redundancy is important
Kendall & Kendall

23. Types of Decision Table