Maintaining Information Systems Class 27

SDLC Project Identification & Selection Project Initiation & Planning Analysis Logical Design Physical Design Implementation Maintenance **

Maintenance Changes made to a system to fix or enhance its functionality Why is it needed?

Types of Maintenance

Systems Life Cycle Design Concept Plan Analyze Design Implement Maintain

System Maintenance Process Obtain maintenance requests SSR, CR, SMR Transform requests into formal changes / Identify what parts of the system need to be changed Secure resources to implement the change Design, Code, TEST, and Implement chages Monitor changes Update HW, SW documentation

Managing Maintenance Controlling maintenance requests Forms Review Committee Planning Who does it?

Managing maintenance (cont) How is effectiveness (quality) measured? Main point: without measuring and/or tracking maintenance activities, you can’t improve. Configuration / Version management

Cost of Maintenance New Development Maintenance 35-40%40-60%70-80% 1970’s1980’s 1990’s

Maintenance Cost Factors Defects Customers Documentation Personnel Tools Software Structure

Programmers Working on Maintenance Programmers on Programmers on Year New Programs Maintenance ,500 1, ,000 35, ,200, , ,000,000 4,000, ,000,000 6,000,000

CASE Tools for Maintenance CASE System Documents (DFDs, Screen Designs) New Source CodeNew System Docs