1 7.2system development life cycle (sdlc) at the end of this topic, students should be able to:...

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7.2 System Development Life Cycle (SDLC)

At the end of this topic, students should be able to:

1. Identify the steps of system development life cycle

2. Describe each step of system development life cycle

Learning Outcome

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What is SDLC ?


Collection of phases that contain set a group of activities in the information system development.

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Steps of SDLCActivities contain five (5) phases

3. Design

4.

Implementation

5.

Maintenance1. Planning

2.

Analysis


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4th phase: Implementation

1st phase: Planning

5th phase: Maintenance.

Review project requests Prioritize project requests Allocate resources Identify project development

team

2nd phase: Analysis Conduct preliminary investigation Perform detailed analysis activities:

- Study current system

- Determine user requirements

- Recommend solution

3rd phase: Design Acquire hardware and

software, if necessary Develop details of the new

or modified system.

Develop programs, Install and test new system Train users Convert to new system

. Perform maintenance activities

. Monitor system performance

. Evaluate system security

SDLC(Major

Activities)

1st phase: Planning

• Begins when the steering committee received a project request

• Committee members usually consists of five to nine members

• example: mix of vice presidents, managers, non-management users, and IT personnel

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1st phase: Planning Review project requests Prioritize project requests Allocate resources Identify project development team

1. Conduct preliminary investigation• Sometimes called the feasibility study

• Defines the problem - The main purpose is to determine the exact nature of the problem or improvement & decide whether it is worth pursuing.

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2nd phase: Analysis

2nd phase: Analysis

1. Conduct preliminary investigation

2. Perform detailed analysis activities:

- Study current system

- Determine user requirements

- Recommend solution

1. Conduct preliminary investigation• Interview the user who submitted the project request and

others users.

• Upon completion of the preliminary investigation, the systems analyst writes the feasibility report to present the team’s findings to the steering committee.

• Decide pursuing or not.

• Four (4) tests to evaluate feasibility of a project:

1. Operational feasibility

2. Schedule feasibility

3. Technical feasibility

4. Economic feasibility 7


2nd phase: Analysis

2. Perform detailed analysis activities:

• Detailed analysis sometimes is called logical design because the systems analysts develop the proposed solution without regard to any specific hardware or software.

• Involves three major activities:

(1) study how the current system works(2) determine the users’ wants, needs &

requirements(3) recommend a solution.

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2nd phase: Analysis

1. Acquire hardware and software• The activity consists of four major tasks:

(1) identify technical specifications (2) request vendor proposals (3) test and evaluate vendor proposals(4) make a decision

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3rd phase: Design

3rd phase: Design

1. Acquire hardware and software, if necessary

2. Develop details of the new or modified system

2. Develop details of the new or modified system

• After the systems analyst identifies the data and process requirements, the next step is to develop detailed design specifications for the components in the proposed solution.

• A detailed design sometimes is called a physical design because it specifies hardware & software — the physical components required — for automated procedures.

• The activities include developing designs for the databases, inputs, outputs & programs.

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3rd phase: Design


• The purpose of this phase is to Construct or build the new or modified system and then deliver it to the user

• Four (4) major activities

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1. Develop programs

2. Install and test new system

3. Train users

4. Convert to new system

1. Develop programs

• If the organization purchases packaged software (no modifications required) the development team may skip this activity.

• For custom software or packaged software, however, programs are developed or modified either by an outside firm or in-house.

• Programmers write or modify programs from the program specification package created during the analysis phase.

• These program development follow an organized set of activities known as the program development life cycle.

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2. Install and test new system

• If the organization acquires new hardware or software, someone must install and test it

• Tests performed during this step include:

1. unit tests - verifies that each individual program or object works by itself.

2. systems tests - verifies that all programs in an application work together properly

3. integration tests - verifies that an application works with other applications.

4. acceptance tests - performed by end- users & checks the new system to ensure that it works with actual data.

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3. Train user

• Training involves showing users exactly how they will use the new hardware and software in the system.

• Some training takes place as one-on-one sessions or classroom style lectures

• Other organizations use Web-based training, which is a self-directed, self-paced online instruction technique.

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4. Convert to new system

• The final implementation activity is to change from the old system to the new system.

• This change can take place using one or more of the following conversion strategies:

1. direct2. parallel3. phased4. pilot

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5th phase: Maintenance

• Provide ongoing assistance for an information system after the system is implemented

• Three (3) major activities

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5th phase: Maintenance.

1. Perform maintenance activities

2. Monitor system performance

3. Evaluate system security

1. Perform maintenance activities• corrective maintenance• adaptive maintenance

2. Monitor system performance• perfective maintenance

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3. Evaluate system security

• All elements of an information system must be secure from threats both inside and outside.

• Users should be allowed access only to the data and information for which they are authorized (Maintain confidentiality)

• Data should be secure so that intruders cannot alter, damage, or steal data. (Ensure integrity and reliability)

• Networks need safeguards to prevent them from being compromised. (Limited access to information)

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Shelly, G.B., & Vermaat, M. (2012). Discovering computers: Your interactive guide to the digital world. Boston, MA: Course Technology/ Cengage Learning.

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REFERENCES


1 7.2system development life cycle (sdlc) at the end of this topic, students should be able to:...

Documents

information system development

modified system

analysis slide

study current system

project development

nd phase

detailed analysis activities

monitor system performance