Answer
An Information system developed for an organization is for all the members of the organization and it is for long run of the organization. It should be able to cater the need of staff of all levels. If proper process is not followed some part of the system will lack essential features which results in the deficiency in operation or people may not own it. Sometimes if the complete process is not followed it may lack the essential report generating process or generated report would miss essential part. Moreover, the rework of the system would be financially very costly. Thus to avoid such deficiency, the design and development phase of system should take complete and should follow the systematic life cycle.
The essential phases of system development life cycle:
a. Requirement Analysis
b. Feasibility Study
c. System Design
d. System Development
e. Testing
f. System Deployment
g. System Maintenance and Support