6.0 SDLC

Chapter 6
System Development Life Cycle (SDLC)

Describe the steps of
System Development Life Cycle

(SDLC)

What is SDLC?

• System development is a set of activities used to build
an information system.

• System development activities often grouped into
larger categories called phases

• This collection of phases sometimes is called the system
development life cycle (SDLC)

• Most SDLCs contain five steps/phases

– Planning
– Analysis
– Design
– Implementation
– Maintenance

Step 1: Planning

Step 5: Maintenance

Step 2: Analysis

Steps in
SDLC

Step 4: Implementation Step 3: Design

Step 1: Planning

 Review project requests
 Prioritize project requests
 Allocate resources
 Form project development team

Step 5: Maintenance Steps in Step 2: Analysis
SDLC
 Perform maintenance  Conduct preliminary investigation
activities
 Perform detailed analysis activities:
 Monitor system • Study current system
performance • Determine user requirements
• Recommend solution
 Assess system security

Step 4: Implementation Step 3: Design

 Develop programs and apps, if necessary  Acquire hardware and
 Install and test new system software, if necessary
 Train users
 Convert to new system  Develop details of system

STEP 1 : PLANNING

• to plan all project processes and activities in
order to ensure project success and to create a
comprehensive set of plans

STEP 1 : PLANNING

ACTIVITIES: Step 1. Planning
1. Review and approve the project requests
1. Review project requests
• steering committee received a project request 2. Prioritize project

2. Prioritize project requests requests
3. Allocate resources
• steering committee will ; 4. Form a project

development team

 evaluates the remaining project requests based on their
value to the organization.

 approves some projects and rejects others.

3. Allocate resources, such as money, people and equipment to

approved projects

4. Form a project development team for each approved

projects

Who participates in the system
development life cycle?

STEP 2 : ANALYSIS

• Study the project in order to determine if it is
worth pursuing and recommend the solution of
the proposed system

STEP 2 : ANALYSIS

ACTIVITIES : Step 2. Analysis

1) Conduct Preliminary Investigation 2. Perform detailed analysis
(also called feasibility study) activities:
• Study current system
Determine the exact nature of the • Determine user requirements
problem or improvement and decide • Recommend solution
whether it is worth pursuing.

Usually System Analyst will conduct using…
(a) Data gathering

There are six (6) techniques:

1. Review documentation
2. Observe
3. Survey
4. Interview
5. Joint -application design (JAD) session
6. Research

STEP 2 : ANALYSIS

ACTIVITIES : Step 2. Analysis
(b) Uses at least 4 feasibility test:

1. Economic feasibility - measure 2. Perform detailed analysis
whether the lifetime benefits of the activities:
proposed information system will be • Study current system
greater than its lifetime costs • Determine user requirements
• Recommend solution

2. Technical feasibility - measures whether the

organization has or can obtain the hardware, software,

and people needed to deliver and support the proposed

information system

3. Schedule feasibility - measure the established

deadlines for the project are reasonable

4. Operational feasibility - measure how well the

proposed information system will work

STEP 2 : ANALYSIS

ACTIVITIES : Step 2. Analysis

2) Perform Detailed Analysis: 1. Conduct preliminary investigation

• Study how the current system works • Study current system

• Determine the user's wants, needs and • Determine user requirements
requirement • Recommend solution

• Recommend a solution by presenting system proposal.
The example of suggestions are:

 buy package software (if available)

 develop custom software

 outsourcing to develop custom software (if no manpower)

 modify current system (if available)

• Use two approach for analysis and design

 process modelling - process that transform inputs into
output

 object modelling - Is an analysis and design techniques

STEP 3 : DESIGN

• Specifying hardware and system requirements
and defining overall system architecture of a
new or modify system.

STEP 3 : DESIGN

ACTIVITIES : Step 3. Design

1) Acquire necessary hardware and software

(if necessary)  Detailed design

• Identify technical specifications
• Solicit vendor proposals
• Test and evaluate vendor proposals
• Make decision

STEP 3 : DESIGN

ACTIVITIES : Step 3. Design

2) Detailed design  Acquire hardware
and software, if

• Design database necessary

• Design input and output interface

• Design program

• Use prototype

 working model of the proposed system

• Use CASE tools

 A software that can assist during system development

STEP 4 : IMPLEMENTATION

• To construct, or build the new or modified
system and then deliver it to the users.

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4.
Implementation
1) Develop program and apps /
 Install and test new
also called program development life cycle system
- To produce custom software
 Train users
 Convert to new system

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4.
 IDmevpelleopmperongtraatmios,nif

2) Install and test the new system necessary

• Systems analysts will test individual programs.  Train users
 To avoid error in the system
 Convert to new system

 To ensure all programs work together in the system

• Tests performed during this step include:

TEST PURPOSE

Unit Test To verifies that each individual program or object works by itself

System Test To verifies that all programs in an application work together
properly

Integration Test To verifies that an application works with other applications

Acceptance Test To checks the new system to ensure that it works with actual data

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4.
 IDmevpelleopmperongtraatmios,nif
3) Train user
necessary
• One-on-one session
 Install and test new
system

• Classroom-style lecture  Convert to new system

• Web-based session

‒ self-directed, self-paced online instruction technique.

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4.
4) Convert to the new system  IDmevpelleopmperongtraatmios,nif

i. Direct conversion necessary

 Install and test new
system

 Train users

User stops using the old system and begins using the new
system on a certain date

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4. Implementation
4) Convert to the new system
 Develop programs, if necessary
ii. Parallel conversion  Install and test new system
 Train users

Consists of running the old system alongside the new system
for a specified time

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4. Implementation
4) Convert to the new system
 Develop programs, if necessary
iii. Phased conversion  Install and test new system
 Train users

Each site converts at a separate time. Larger systems that
have multiple sites often use a phased conversion.

STEP 4 : IMPLEMENTATION

ACTIVITIES : Step 4. Implementation
4) Convert to the new system
 Develop programs, if necessary
 Install and test new system
 Train users

iv. Pilot conversion
Only one location in the organization uses the new
system - so that it can be tested. After the pilot site
approves the new system, other sites convert using
one of the other conversion strategies.

STEP 5 : MAINTENANCE

• To provide ongoing assistance for an information
system and its users after the system is implemented.

• To ensure the information system is fully functional
and performs optimally until the system reaches its
end of life.

STEP 5 : MAINTENANCE

ACTIVITIES : Step 5 Maintenance

 Perform maintenance

1) Performed maintenance activities activities
 Monitor system

fixing errors in, as well as improving a system performance
 Assesses system security
operations.

2) Monitor system performance

to determine whether the system is inefficient or unstable at
any point

3) Assess system security

Chief security officers develops a computer security plan that
protect the organization's information assets

Glossary

TERM DESCRIPTION

System Analyst Person responsible for designing and
developing an information system (IS)

Steering Committee Is a decision-making body in a company

Project Team A group of people that consists of users,
Feasibility study the system analyst, other IT professional

System Proposal Investigation to see the problem and
decides whether it is practical and
beneficial to build the system.

Document that assesses the feasibility of
each alternative solution and then
recommends the most feasible solution for
akmpyroject

Glossary

TERM DESCRIPTION
Prototype
Custom software Working model of a proposed system

Package software A software that performs functions specific
Outsourcing to the company/organization. It develop
Vendor based on user needs

Is mass-produced, copyrighted, prewritten
software available for purchase

A source outside company develop
software for the company

Outside company that agree to develop
software for the company/organization

Pop Quiz 。。。

• Why Analysis step is important in SDLC?
• What are the activities of the design step of SDLC?
• If company have insufficient IT support, what the

suggestion for Information System (IS)?
• Why is the development methodology of a system

cyclic ?
• What should one do when the maintenance cost is

more expensive than the cost of purchasing or buying
the IS?