Planning for System Development: Models Used for and Types of System Development Life-Cycle

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Information System (CS507)

LESSON 17

Planning for System Development

The management should prefer to have a plan for IT development so as to help it to take various software

development projects in a structured way. At the very start, planning is done by the management regarding

following issues

Scope of software development certain selected areas or the entire organization.

How to get the project done in-house committee or hired consultants.

How much resource and time commitment can be made.

Any written policy on which model is needed to be followed for software development.

IT planning provides a structured means of addressing the impact of technologies, including emerging

technologies, on an organization. Through the planning process, relevant technologies are identified and

evaluated in the context of broader business goals and targets. Based on a comparative assessment of

relevant technologies, the direction for the organization can be established. Business planning is an accepted

responsibility of management. Plans provide a direction and framework for action. Plans enunciate

business goals and the actions that need to be initiated to achieve those goals including related benefits,

resources and timeframes.

Increasingly, information technologies not only support but, also may drive or enable business strategies. In

this context information technologies are an integral part of the business planning process itself. If such

potential is evident after the completion of the business plan, then the business plan must be revisited and,

if appropriate, revised.

17.1 Phases of IT planning

Although information technology plans are unique, the planning process and the underlying activities are

similar.

Orientation -- This start-up phase is required to establish the scope of the plan and the methodology

and techniques to be applied

Assessment -- Major steps in this phase are

· Confirm business direction and drivers;

· Review technology trends; outline future requirements;

· Inventory existing information systems; and

· Develop an assessment of what is needed.

· In the concluding step of this phase there should be a well-developed assessment of the current and

future business needs,

Strategic Plan -- This phase commences with developing the vision and desired future positioning of

information technology within the organization.

Tactical Plan -- The selected strategies are divided into a series of projects which are scheduled for

implementation depending upon relative priorities and resource availability. The planning process is

Information System (CS507)

concluded by recommending a monitoring and control mechanism.

What is System Development?

System development refers to the structuring of hardware and software to achieve the effective and

efficient processing of information. Information systems are developed keeping in view the needs to be

met. There can be two reasons for system development.

A manual information system is to be computerised.

An already computerised information system is to be replaced with a system that addresses the

growing and changing needs of the organization or the old system has become too slow or there

are newer more efficient and user friendly development tools are available.

In both the above mentioned situations, the phases followed for system development would be the same.

The extent of system study, analysis & design may depend on the fact whether the existing system is manual

or computerised. To develop systems, various development models or techniques are deployed. Let us

understand why these development models are used.

17.2 Models Used for System Development

Initially software development consisted of a programmer writing code to solve a problem or automate a

procedure. Nowadays, systems are so big and complex that teams of architects, analysts, programmers,

testers and users must work together to create the millions of lines of custom-written code that drive our

enterprises. To manage this, a number of models for system development have been created. The most

famous of these models is the system development lifecycle model (SDLC) or Lifecycle Models.

17.3 Systems Development Life Cycle

System Development Life Cycle (SDLC) is the overall process of developing information systems through a

multi-step process from investigation of initial requirements through analysis, design, implementation and

maintenance. SDLC is also known as information systems development or application development. SDLC

is a systems approach to problem solving and is made up of several phases, each comprised of multiple

steps. It describes the stages a system passes through from inception until it is discarded or replaced. SDLC

provides

Structure

Methods

Controls

Checklist

Project lifecycle vs. SDLC

The systems development life cycle is a project management technique that divides complex projects into

smaller, more easily managed segments or phases. Segmenting projects allows managers to verify the

successful completion of project phases before allocating resources to subsequent phases. Although System

development can be seen as a project in itself, but the attribute that makes system development different

from regular projects is that a project has a definite end and it is unlikely that ongoing maintenance will be

included in the scope of the project but this falls in the definition of SDLC.

17.4 Types of System Development Life-Cycle Model

Information System (CS507)

The concept of system development lifecycle model has been explained in various shapes and forms. The

concluding form follows the same spirit except for minor differences.

Waterfall model / Classic lifecycle/ Linear Sequential Model

The waterfall model is a software development model (a process for the creation of software) in which

development is seen as flowing steadily downwards (like a waterfall) through the various phases

Incremental Models

In incremental models, software is built not written. Software is constructed step by step in the same way a

building is constructed. The products is designed, implemented, integrated and tested as a series of

incremental builds, where a build consists of code pieces from various modules interacting together to

provide a specific functional capability and testable as a whole.

Iterative Models

In these models customer feed back is taken at each phase and project is modified accordingly if need be.

Prototypes are used in these models.

Need Assessment

Information systems are usually developed on need-basis, that is, problems and opportunities arise and

render system development necessary. In this phase the stakeholders must attempt to come to some

understanding of the nature of the problem or opportunity they are addressing. Issues which can be

considered in this phase are. Is the problem

Well structured/Structured -- constrained problems with convergent solutions, limited number

of rules and principles within well-defined parameters.

Unstructured -- multiple solutions, fewer parameters, and contain uncertainty about which

concepts and rules.

Should formal terms of reference be prepared and approved by the steering committee or project

committee? This depends on the size, impact and cost of the system being prepared. The TOR usually

covers following aspects.

Investigation on existing system

Definition of system requirements

Specifying performance criteria for the system

Detailed cost budget

Draft plan for implementation

If the problem is decided to be addressed and the level of acceptance that exists among the stakeholders on

the need of change. The level of technological uncertainty the proposed solution to the

problem/opportunity has. The most critical phase is the agreement of the stakeholders on the definition of

problem and parameters of solution.

Entry and Feasibility Study

The purpose of this phase is to obtain a commitment to change and to evaluate whether cost effective

solutions are available to address the problem or opportunity that has been identified. Following examples

can be considered to explain this situation.

Information System (CS507)

Say a problem has been recognized by a group of users. They believe they can design and

implement a solution themselves using a high level language. Their proposed system will have

little impact on others within the organization, nor will it be material from the viewpoint of the

overall organization. In this situation, the users are already motivated to bring about change.

Thus activities to accomplish successful entry are minor or unnecessary.

On the other hand, consider a solution where potential solutions will have a widespread impact

on the overall organization. Activities to accomplish successful entry are now critical.

Information systems professionals must seek to establish themselves as legitimate change

agents among the stake holders. Moreover they must seek to foster among the stakeholders a

commitment to change. If potential solutions will have a significant impact on task and social

systems, a spirit of collaborative analysis and evaluation among stakeholders must be

developed.

Once the entry is successful, a preliminary study can be carried out to evaluate the feasibility of the new

system. A Feasibility study team should be constituted

Draw representatives from the departments affected by the project

At least one person must have a detailed knowledge of computers and systems design (called

system analyst).

At least one person should have a detailed knowledge of

The organization

How current system operates

Information needs of the system

Defects in the existing system

Consultants from the outside

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