Cyber InfoTechnology

WEEK 06


REFLECTION IN THIS WEEK

         This week, I have learned a lot of things as what you can see in this page. I have learned the Information System and the Information System Development Methodologies. Information System Methodologies is a collection of procedures, techniques, tools and documentation aids which will help the systems developers in their efforts to implement a new information system.

INFORMATION SYSTEMS

IS DEVELOPMENT METHODOLOGIES DEFINITION

IS Development Methodologies contain models and reflect 

particular perspectives of ‘reality’ based on a set of 

philosophical paradigms. A methodology should tell you 

‘what’ steps to take and ‘how’ to perform those steps but most 

importantly the reasons ‘why’ those steps should be taken, in 

that particular order.

Jayaratna, (1994)pg. 37

WHY USE A METHODOLOGY?

EVOLUTION OF IS DEVELOPMENT METHODOLOGIES

ELEMENTS OF METHODOLOGY

TYPES OF ISD METHODOLOGY

GANE ANS SARSONS (STRADIS)

•Chris Gane and Trish Sarson introduced their ideas on systems analysis and design in the late 1970's.

•The methodology remains today as one of the most popular techniques for structured analysis and design of systems.

•The Gane & Sarson method is based on the building of a logical model of the system, using graphical techniques to enable users, analysts, and designers to get a clear and common picture of the system and how its parts fit together to meet the user's needs.

•The methodology involves building a system top-down by successive refinement. First, an overall system data flow is created. Then, detailed data flows are created. Next, the details of the data structures and the process logic is determined. Finally, design of modular structures is begun.

•The focus of analysis in the Gane and Sarson method is the Data Flow diagram, which is used to describe the processes of the system, and how the processes transform data.

INFORMATION ENGINEERING (IE)

JACKSON SYSTEM DEVELOPMENT

•JSD are about features of the system to be built. JSD were widely used in the 1970's and 1980's in Great Britain and in Sweden.

•JSD is a method of system development that covers the software life cycle either directly or, by providing a framework into which more specialized techniques can fit.

•JSD is a technical method. Other technical methods include Structured Analysis and Design and Object-Oriented Systems Analysis and Design.

•The purpose of technical methods is to give developer assistance in thinking about the structure of software development problem and its solution, what functions and processes the system must perform, what data it must remember, the events that trigger the running of the processes, and so on.

PROTOTYPING /ITERATIVE APPROACH

STRUCTURED APPROACH (SDLC)

•The oldest and most known methodology used to coordinate the efforts of information systems development is known as the “Waterfall”.

•The model is based on a set of generic life cycle stages to guide developers from an initiating through maintenance of the completed systems.

•is defined as the process (as a whole) of developing system or software to meet certain requirements.

•It covers many activities starts from understanding why the system should be built, studying the project feasibility, analyzing problems, choosing the system design and architecture, implementing and testing it, up to delivering the system as product to the user.