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STRUCTURED DESIGN

Part 1: An Introduction to Structured Techniques
by George Martin

Start ý Sequence ý Selection ý Iteration/Looping ý Testing ý Nassi-Schneiderman Charts ý Sources and PDF

SEQUENCE

First, letýs take a look at the sequence structure. The sequence of operations is A, B, and C (see Figure 1). This sequence has one entry point and one exit, a key premise of structured design. The operations A, B, and C may be complicated routines, but testing is straightforward and can be completed with a certainty that youýve done it correctly.

Figure 1ýHere you can see the sequence of operations A, B, and C.

Many times A, B, and C are referred to as processes. These processes can be as simple as performing an arithmetic operation (a = b + c) or as complicated as RepaintTheUsersScreen(). Also, they can be referred to as a single process. Letýs call it process ABC (see Figure 2).

Figure 2ýThe sequence of operations A, B, and C can be referred to as process ABC.

You can divide and conquer, break it down into modules, or structure that design. You have a building block that can start small, be tested, and grow to unlimited size and complexity. As I describe different types of structures, notice that they all have one entry and one exit. All the structures can be thought of as or reduced to a simple sequence structure, which is completely understandable and testable.

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