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AVCE ICT Unit 7 - Programming

Session 8 – Documenting your programs

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Program design

You should have analysed the user requirements and produced a specificationThis is only the start of the design process – you might have to “return to the drawing board” many times before the program is finished

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The Software Development Lifecycle

This is an idea used by software designers that the whole process can be thought of as a cycleThe stages are: Analyse the problem Produce a specification Produce the program Test it Evaluate how well it met the original

need

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The Software Development Lifecycle

Can be a linear process Start at one end and work to the other

A circular process If it didn’t meet the original needs

totally, go back to the start refining your original idea

This can also be thought of as a spiral Hopefully, you will reach the end

where no further refinement is needed

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Documentation

This is the weak point for many programmersIt isn’t a good idea to do all design work on a computerYou wouldn’t start building a house without plans!

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Documentation

Sketches can be used to show the user interfaceThe program flow can be shown by using Jackson Structure Diagrams or flowchartsCode can be written in a general form called structured English or pseudocode This can then be converted into any programming language

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Documentation

Design happens in stages and your documentation should be broken down to show thisUsing VB, many programmers start with the interfaceThey then code the controls as neededYou still need to have an overall plan though

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Flowcharts

Can be used to show program flowUse standard symbols A

Process

A decision (If…..Then)

Start or End

Disk storage

Manualinput

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Task

Prepare a flowchart for making beans on toastPrepare a flowchart for a program that adds together two numbers

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Jackson Structure Diagrams

These are diagrams that show the sub procedures that make up a whole programDeveloped by one Michael Jackson (honestly) in the 1970sThey are “read” from left to rightMajor processes are shown along the topElementary (the most broken down) sub processes are shown along the bottom

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Assignment tasks

You will be required to produce several pieces of documentation: A user manual Technical documentation including

specification, design diagrams, pseudocode, interface design plus actual screen images and code printouts

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Jackson Structure Diagrams

Symbols are used in the box to show if it is an iteration (loop) processOr a selection (If …Then) processOrdinary sequential flow does not have an additional symbolThe handout has tasks to complete

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