The systems analyst approaching process specifications and structured decisions has many options for documenting and analyzing them. In Chapters “Using Data Flow Diagrams” and “Analyzing Systems Using Data Dictionaries” you noted processes such as VERIFY AND COMPUTE FEES, but you did not explain the logic necessary to execute these tasks. The methods available for documenting… [Continue Reading]
Process Specifications and Structured Decisions
Overview of Process Specifications
To determine the human information requirements of a decision analysis strategy, the systems analyst must first determine the users’ objectives, along with the organization’s objectives, using either a top-down approach or an object-oriented approach. The systems analyst must understand the principles of organizations and have a working knowledge of data-gathering techniques. The top-down approach is… [Continue Reading]
Process Specification Format
Process specifications link the process to the data flow diagram, and hence the data dictionary, as illustrated in the Figure 1 below. Each process specification should be entered on a separate form or into a CASE tool screen. Enter the following information: The process number, which must match the process ID on the data flow… [Continue Reading]
Writing Structured English
When the process logic involves formulas or iteration, or when structured decisions are not complex, an appropriate technique for analyzing the decision process is the use of structured English. As the name implies, structured English is based on structured logic, or instructions organized into nested and grouped procedures, and simple English statements such as add,… [Continue Reading]
Developing Decision Tables
A decision table is a table of rows and columns, separated into four quadrants, as shown in the table illustration below. The upper left quadrant contains the condition(s); 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… [Continue Reading]
A Decision Table Example
Table below is an illustration of a decision table developed using the steps previously outlined. In this example a company is trying to maintain a meaningful mailing list of customers. The objective is to send out only the catalogs from which customers will buy merchandise. The managers realize that certain loyal customers order from every… [Continue Reading]
Drawing Decision Trees
Decision trees are used when complex branching occurs in a structured decision process. Trees are also useful when it is essential to keep a string of decisions in a particular sequence. Although the decision tree derives its name from natural trees, decision trees are most often drawn on their side, with the root of the… [Continue Reading]
