Homework 2 A Simple Data Flow Diagram

Due: Thursday, September 17, 12:30 PM

Introduction

This assignment is based on a chapter from Structured Analysis and System Specification, by Tom DeMarco. This book was one of the first to formalize the process of system analysis with tools that mirrored the advances of the structured programming movement of the 1970s. It is still one of the great books of software engineering.

Tasks

1. Draw a feasible Data Flow Diagram 3 for DeMarco's analysis of APT.


2. Select two of the data flows for which DeMarco has not already provided data definitions, and write data definitions for them. These will become part of the Data Dictionary for the spec. Your answers will reflect your understanding of how such a system works.


3. Select one bubble each from two of the second-level diagrams, and write process descriptions for them. You may use Structured English patterned after Figure 43, or you can use a decision tree, decision table, or other pseudocode for your descriptions.

As DeMarco says in Section 8.6, "There is no 'right' answer [for Task 1] -- your DFD will reflect your concept of how the Credit Department probably works. But make sure it is not demonstrably wrong." Similarly, there will is no particular right answer for Tasks 2 or 3. Your answers will reflect your understanding of how such a system might works. Just be sure that your answers aren't demonstrably wrong; that is, they should not contradict another part of the analysis.

Deliverables

By the due date and time, submit your answers in hard copy, in a respectable form.