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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

Sometimes I start to write an article, and I find myself at a loss for words. Well, I had no such problems this month. Iýd like to present a concept called structured design (or structured programming) and, in particular, how it pertains to flowcharts. Perhaps youýve heard of structured design or have taken a course or two about it. My career was timed just right so that I ran into complicated software projects at the same time a lot of work was developed with structured techniques. It was helpful and stuck with me. In case youýve never come across this or have forgotten, let me refresh your memory.

In the late ý60s and early ý70s, programs started becoming so complex that it was increasingly difficult to understand them. Where we once had paper, tape, and card decks, there was now floppy disk program storage. Writing and editing large programs was made easier, and the number of lines of code a programmer could control soared. However, these larger programs were ill conceived and poorly implemented. Jumps within the program were so frequent that logical program flow was not obvious and debugging was nearly impossible, often referred to as spaghetti code. To overcome this situation, software engineering was developed and structured programming was born.

One key principal of structured programming in a structured design is that every program can be created with a limited number of structural elements. Some experts say that all you need is sequence, selection, and iteration, and I agree. Letýs look at these elements.

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