26-07-2012, 01:28 PM
Review of the Traditional Methodologies
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A Traditional (software development) methodology or system development methodology in
software engineering is a framework that is used to structure, plan, and control the process of
developing an information system.
History
The Traditional (software development) methodology framework didn't emerge until the 1960s.
According to Elliott (2004) the systems development life cycle (SDLC) can be considered to be
the oldest formalized methodology framework for building information systems. The main idea
of the SDLC has been "to pursue the development of information systems in a very deliberate,
structured and methodical way, requiring each stage of the life cycle from inception of the idea
to delivery of the final system, to be carried out in rigidly and sequentially". The main target of
this methodology framework in the 1960s was "to develop large scale functional business
systems in an age of large scale business conglomerates. Information systems activities revolved
around heavy data processing and number crunching routines".
The traditional Approach
The traditional approach is also called structured methodology which is most commonly been used for
so many years. Shelly, Cashman & Rosenblatt, 2006, points out that structured methodology uses a
series of phases, called System development life cycle (SDLC), in order to plan, analyse, design,
implement and support a computer based information system. According to Rob, 2006, System
Development Life cycle (SDLC), refers to the necessary process for the successful development of the
information system. These necessary processes include some phases and some activities. The phases
involved in SDLC are the following.
• System planning.
• System analysis.
• System Design.
• System implementation.
• System operation, support and security.
Traditional approach adopts step-by-step approach to go through the above phases. The phase or
activities of one step should be completed before moving to the next step. The structured approach
looks the system from a top down view. George, Hoffer & Valacich, 2006, points out that the steps or
phases in SDLC may vary in each organization according to its goals and it is also possible to complete
some activities in one phase in parallel with some other activities of another phase. Sometimes these
phases are repeated until an acceptable system is found. SDLC is traditionally pictured as a water fall
model, where the end product of each phase flows sequentially to the next phase. This methodology is
called waterfall model because it moves forward from one step to another in the same manner as a
water fall. It is also possible to go backward from one step to another.
System planning
Dennis, Roth & Wixom, 2006, states that the system planning phase is the fundamental process of
understanding why an information system should built in an organization and determining how it would
be implemented. According to George, Hoffer & Valacich, 2006, first phase in the SDLC, system planning,
has two primary activities.
• First someone identifies the need for a new system or notifies the desired changes in the existing
system.
• Second task is to investigate the system and determine the scope of the proposed system.
In the first step In the first step, the IT department gets a formal request which is called a system
request, which demands a new information system or desired changes in the existing information
system. A system request can come from top managers, staffs, other departments or from the IT
department itself. The second step involves a preliminary investigation to identify the nature and scope
of the opportunity for a new system or the problem with the existing system. According to Shelly,
Cashman & Rosenblatt, 2006, the preliminary investigation is a critical step because the outcome of this
investigation will affect the entire development processes. The IT department conducts a feasibility
study which is a key part of the preliminary investigation, to review anticipated costs and benefits of the
proposed project. The feasibility study may recommend business process review or a IT solution
depending upon the technical, operational, economic and time factors. If the preliminary investigation
finds out that a full-scale system review is necessary, then the next step is system analysis.
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System analysis
The purpose of the second phase of the SDLC, system analysis, is to build a logical model of the new
system. According to Dennis, Roth & Wixom, 2006, system analysis phase find out information about
who will use the system, what will do the system, and when and where the system will be used. The
initial step in the system analysis phase is requirement modelling. The system analyst gathers the
requirements of the proposed system. The requirements are gathered by using several fact finding
techniques such as interviews, surveys, document reviews, observation and sampling. These fact finding
results are used to build initial models. The system analysts compare these models to determine which
model is most satisfying the requirements with in the cost, labour and the technical levels. So the end
product of the system analysis phase is a system requirement document which describes the
requirements and alternative solution for the proposed information system.
System Design
According to Shelly, Cashman & Rosenblatt, 2006, the purpose of the third phase of SDLC, system
design, is to create a blue print that satisfies all the requirements documented for the proposed system.
In the design phase the logical design turns into physical or technical specification. Dennis, Roth &
Wixom, 2006, points out that the first step in the system design is the development of a design strategy
which clarifies whether the system will be developed by the organization’s own programmers, whether
the development process will be outsourced to another company, or whether the company will buy an
existing software package from some vendors. The application architecture is also designed during the
system design phase. The application architecture will help the programmers by showing how to
transform the logic design into different program modules and code. During this phase, the internal and
external controls and the user interface of the system are designed. All the aspects of the system from
inputs and output screens to reports, databases and computer process are designed during the system
design phase. So the final product of system design is documented in the system design specification
and will be submitted to review committee for approval. At the end of the design phase review
committee will re-examine the feasibility analysis and project plan and will decide whether the project
should continue or terminate.
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System Implementation
During the system implementation the system specifications turn into a working system that is tested
and put into use. System implementation phase includes coding, testing and installation. If the system is
purchased the system analysts configure the system and make necessary changes to meet the
requirements of the organization. At the end of this phase the system is ready for use and the system
becomes a part of the daily activities of the organization. Testing will be done to clarify that there is no
errors associated with the system operation. Processes like converting data into system’s files and
training users are done at the end of this phase. A system evaluation is made at the end of this phase in
order to determine whether the system operates properly and to ensure that the costs and benefits are
within the expectation.
System Operation, Support and Security
The objectives of this phase are maintenance, enhancement and protection of the system. Maintenance
deals with correcting errors and adapt to the changes in the business environment. Support provides
options to add new features to the system to improve the efficiency. Security provide safeguard to
internal and external threats. According to Shelly, Cashman & Rosenblatt, 2006, the objective of this
phase is to maximize the return on the investment made for the information system.
Development Methodology
A software development methodology is a framework that is used to structure, plan, and control
the process of developing an information system - this includes the pre-definition of specific
deliverables and artifacts that are created and completed by a project team to develop or maintain
an application.