System Development Life Cycle Methodology
Learning Objectives :
To introduce the general concepts of various approaches of systems development, their framework, advantages and disadvantages;
To explain in detail the phases involved in Systems Development Life Cycle(SDLC);
To understand the key issues while acquiring or developing system for achieving goals set;
To discuss in detail various System Development Tools like – DFD, Decision Tree, Flowcharts etc.; and
To understand the auditors’ role in SDLC.
Information systems serve many different purposes, ranging from the processing of business transactions - to provide information needed to decide recurring issues, assisting senior officials with difficult strategy formulation, and linking office information and corporate data. But how do such complex information systems come into existence? Of course, through people. Technology has developed at a rapid pace but the most important aspect of any system is human know-how and the use of ideas to harness the computer so that it performs the required tasks. This process is essentially what system development is all about. To be of any use, a computer-based information system must function properly, be easy to use, and suit the organization for which it has been designed. If a system helps people to work more efficiently they will use it. If not, they will surely avoid it.
2.2 System Development Process
In business, systems development refers to the process of examining a business situation with the intent of improving it through better procedures and methods. System development can generally be thought of as having two major components : System Analysis and System Design. •
System Analysis is the process of gathering and interpreting facts, diagnosing problems, and using the information to recommend improvements to the system.
System Design is the process of planning a new business system or one to replace or complement an existing system.
But before planning can be done, one must thoroughly understand the old system and determine how computers can be used (if at all) to make its operation more effective.
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Information Systems Control and Audit
Example : Consider stockroom operations of a clothing store. What measures can be taken to control its inventory and gain access to more up-to-date information about stock levels and reordering in a better way.
Solution : The Stores Manager asks a System Analyst to organize the stockroom operations. Before an analyst can design a system to capture data, update files and produce reports, he needs to know more about :
how the store currently operates,
what forms are being used to store information manually, such as requisitions, purchase orders and invoices etc,
what reports are being produced and how they are being used, etc.
To proceed, an analyst seeks information about lists of reorder notices, outstanding purchase orders, records of stock on hand, and other reports. He tries to understand how the existing system works and more specifically what the flow of information through the system looks like and assesses as carefully as possible, what the future need of the system will be and what changes should be considered to meet these needs. He may recommend alternatives for improving the situation which then management decides to accept or reject. The plan includes all system design features, file specifications, operating procedures, and design features, and equipment and personnel requirements. The system design is like the blue print for a building, it specifies all the features that should be there in the finished product.
Achieving System Development Objectives: There are many reasons why
organizations fail to achieve their systems development objectives. Some of them are as follows : •
Lack of senior...