SAD

3/5 exam

Ch 2: System Development Life Cycle Phases (SDLC)

• Preliminary Investigation

• System Analysis

• System Design

• System development

• Implement and Evaluation

SDLC Definition

A structured framework used to guide the development of information systems, covering the entire process from conception to implementation and maintenance.

SDLC Purpose

To provide a structured and systematic process for managing and controlling the development of information system ensuring consistency, quality, and efficiency.

The Waterfall Model

• Linear and sequential approach to software development

• Best suited for projects with clear objectives and well-defined requirements

• Each phase must be completed before moving on to the next; less flexible

Systems Request

• A written request from the client or end-user that initiates the start of the SDLC

• The end user/client identifies the IS and nature of the work that must be done

• Expressed as a problem statement and the improvements desired

Preliminary Investigation Purpose

To identify clearly the nature and scope of the problems mentioned in the systems request

Preliminary Investigation Description

System analyst conducts a simple examination of IS, its problems and produce PI report. The report specifies the identified problems within the system and what further action is recommended.

1/3 actions recommended

1. No problem exists = no further action needed

2. If problem & solution minor, recommend to proceed to phase 4: System Development

3. If further detailed investigation, proceed to System Analysis (phase 2)

System Analysis definition

Process of gathering and interpreting facts, diagnosing problems and using the information to recommend improvement to the system.

System Analysis Purpose

To learn exactly what takes place in the current system, determine and document in detail what should take place, make recommendations to client on alternative solutions and costs

Systems Design

Process of planning a new system to replace or complement an existing system.

Systems Design Purpose

To determine how to construct the IS to best satisfy the documented requirements

Systems Development

IS is constructed for application programs to be written, tested and documented, operational documentation and procedures are finalized, client/end-user review and approval are obtained to ensure system alignment with requirements.

Systems Implementation and Evaluation Key Activities

• Data Conversion - transition data to the new system’s files

• End-User training - final training for users of the new system

• System transition - shift from old system to the new one

Advantages of SDLC

• Phase reviews

• Formal documentation

• Focus on goal achievement

• Delivering quality

• Stakeholder satisfaction

Objectives of PI

• Understand the true nature of the problem

• Define the scopes and constraints of the proposed project

• State the potential benefits

• Provide time and cost estimates

• Prepare and present the PI report

Challenges of PI

• Incomplete/Inaccurate info

• Resistance from employees/management

• Limited time & budget

• Scope creep

• Difficulty in estimating costs & benefits

• Technical constraints

Sub stages Systems Analysis

• Requirement Determination (IRD)

• Requirement Analysis

Requirement Determination : Fact finding techniques

• Interviews

• Questionnaire/Survey

• Observation

• Sampling/Document review

• Research & site visits