Object oriented design goal-driven and pattern-based approach
Various Approaches for Systems Analysis and Design
University of Missouri, St. Louis
In the effort to improve the systems analysis and design processes, different approaches have been, developed. The traditional waterfall approach focuses on compartmentalizing project into several phases. The agile approach focuses on self-adaptive processes with an emphasis on individual talents. The object-oriented approach focuses on combining data and processes into objects and shares the iterative development approach of the agile method. The approaches all have different advantages and disadvantages in a way that they could be, used to fit and optimize different kinds of projects.
Traditional waterfall SDLC
Traditional methods demand complete and accurate requirement specification before development; agile methods presume that change is unavoidable and should be, embraced throughout the product development cycle.6
The individuals who fill those roles are more important than roles that people fill. Fowler believes that each talented individual bring something unique to the development team and disagrees with the application of engineering principles that viewed people as interchangeable units.
Modeling tools aren't nearly as useful as you think
You need a wide variety of modeling techniques in your intellectual toolkit
The object oriented approach looks at a system from a bottom-up view. It combines data and processes (methods) into objects. Within an information system, objects could be customers, suppliers, contracts, and rental agreements. A set of diagrams or models is, used to represent various views and functionality of the system and is commonly, known as Unified Modeling Language (UML). The OO approach later becomes, known as the unified process when these models are, used along with a particular method of systems development. Unified process is an iterative and incremental approach to systems development. 4
The goal of OOAD is to improve system quality and productivity of systems analysis and design by making it more usable. Objects are, grouped into classes to share structural and behavioural characteristics. OOAD also incorporates the use of inheritance; it allows the creation of new classes that share the characteristics of existing classes. Similar to the agile methodologies, the object-oriented approach to systems development is similar in the way of iterative development approach. 1
Trade-off issue: concerns how to resolve conflicting requirements
It is also important to note that the OO model has no well-accepted standards. Therefore, these models very significantly from one development to another, some variability in the analysis models' content and structure is unavoidable.9
Comparing between agile methods and traditional methods, as demonstrated in table 1-1, agile methods seems to be more suitable for small IS projects, and traditional method seems to be more suitable for larger scale projects.
References
Figures
Texts:
1. Hoffer, J., George, J., & Valacich, J. 2006.Modern systems analysis and design 6th. Prentice Hall: U.S.A.
6. Cao, L., Ramesh, B. 2007. Agile software development: ad hoc practices or sound principles. IEEE computer Society: 41-47.
7. Ambler, S. 2002. Lessons in agility from internet-based development. IEEE software: 67-73.
