PROGRAMMING

Computer Programs  A series of instructions to the computer  pre-written/packaged/off-the-shelf, or  custom made  There are 6 steps to creating a program

Step 1: Program Specification  Define what you want to do l Program Objectives l Desired Output l Expected Input l Processing Requirements l Documentation of Specs What, not how

Step 2: Program Design  Decide HOW it will be done  Use Structured Programming Techniques l top-down design l psuedocode l flowcharts l 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 l Syntax l Logic  Test using various types of input data  Beta Testing by outside users

Step 5: Program Documentation  An ongoing process  Document how program was developed l Describe what each module does and how  Operator Manuals  Repair Manuals

Step 6: Program Maintenance  The longest part of the process  Fix errors found during operation  Upgrade program to meet changing needs

An Iterative Process  Each step is not completed on its own  Steps overlap, often done in parallel  “Write a little, test a little”  “Software doesn’t break. It is written broke.”

Programming Languages  Machine Language  Assembly Languages  High Level Languages  Problem Oriented Languages  Natural Languages

The Challenge  Software development is a “cottage industry”  The most expensive part of a system  How can we make it more efficient?