PROGRAMMING

Computer Programs

A series of instructions to the computerpre-written/packaged/off-the-shelf, orcustom madeThere are 6 steps to creating a program

Step 1: Program Specification

Define what you want to do Program Objectives Desired Output Expected Input Processing Requirements Documentation of Specs

• What, not how

Step 2: Program Design

Decide HOW it will be doneUse Structured Programming Techniques

top-down design psuedocode flowcharts logic structures

Step 3: Program Coding

Translate the design into computer language

Step 4: Program Testing

Fixing errors is called “debugging”Two types of errors

Syntax Logic

Test using various types of input dataBeta Testing by outside users

Step 5: Program Documentation

An ongoing processDocument how program was developed

Describe what each module does and howOperator ManualsRepair Manuals

Step 6: Program Maintenance

The longest part of the processFix errors found during operationUpgrade program to meet changing needs

An Iterative Process

Each step is not completed on its ownSteps overlap, often done in parallel“Write a little, test a little”“Software doesn’t break. It is written

broke.”

Programming Languages

Machine LanguageAssembly LanguagesHigh Level LanguagesProblem Oriented LanguagesNatural Languages

The Challenge

Software development is a “cottage industry”

The most expensive part of a systemHow can we make it more efficient?