Chapter 11 - Describing Process Specifications and Structured Decisions

1. Methods Available
2. Overview of Process Specification
   goals of producing process specificiations:
   1. to reduce ambiguity of the process
   2. to obtain a precise description about how a process works.
   3. to validate the systems design
   categories that do not require specs:
   1. input/output processes
   2. simple data validation processes
   3. prewritten code processes

   Process Specification Format (Fig. 11.2)

   1. process # (matches the process ID on the DFD)
   2. process name (matches the name displayed on the DFD)
   3. brief discription of what the process accomplishes
   4. list of data input flow (from DFD and data dictionary)
   5. list of data output flow (from DFD and data dictionary)
   6. type of process (batch, online, manual)
   7. names of subprograms or functions contained within prewritten code
   8. description of process logic
   9. reference to structured English, decision table, or decision tree
   10. unresolved issues, incomplete portions of logic, other concerns.
3. Structured English
   1. Express all logic in terms of sequential, decision (case) or iteration structures
   2. Captialize keywords
   3. Indent blocks of statements
   4. Underline words defined in the data dictionary
   5. Clarify logic statements (and , or, greater than, greater than or equal to)
4. Decision Tables
   

   Conditions and Actions	Rules
   Conditions	Condition Alternatives
   Actions	Action Entries

   1. determine the number of conditions that may affect the decision
   2. determine the number of possible actions that can be taken
   3. determine the number of condition alternatives for each condition (Y or N)
   4. Maximum number of columns = # of alternatives ^ number of conditions
   5. Fill in the condition alternatives
   6. Insert X's where rules suggest an action
   7. Combine rules where an alternative doesn't make a difference in the outcome
   8. Check the table for impossible situations, contradictions, and redundancies
   9. Rearrage the conditions / actions if necessary
5. Decision Trees
   1. Identify all conditions and actions and their order and timing.
   2. Begin building the tree from left to right while making sure you are complete in listing all possible alternatives before moving over to the right.
6. Choosing a Structured Decision Analysis Technique
   1. Use structured English when
      1. There are many repetitious actions.
         OR
      2. Communication to end user is important.
   2. Use decision tables when
      1. Complex combinations of conditions, actions, and rules are found.
         OR
      2. You require a method that effectively avoids impossible situations, redundancies, and contradictions.
   3. Use decision trees when
      1. The sequence of conditions and actions is critical
         OR
      2. When not every condition is relevant to every action.
7. Physical and Logical Process Specifications

Transparencies

Exercises: (due - noon Oct. 29, 1998)
e-mail to summers_wayne@ColumbusState.edu your answers to the following problems: pg. 375: 1,2,3

turn in on Oct. 20th a solution to Group Project # (this may be completed in a small group of 3 to 4 students)
Explore the MRE HyperCase company and e-mail the answers to the question #1 on page 374[This can be done in a group of 2-3]