Disadvantages Of System Development Methodology

System development methodologies
History
The system development methodologies also known as SDM never came before 1960s. According to the Elliott 2004 the oldest formalized methodology is the system development life cycle (SDLC). This is well organized methodology framework for building information systems.
The system development methodology is a framework which is used to plan, structure & control the process of develop or maintain information system. The methodologies that are being created for the development of the project depend on the project aims and goals. A formalized approach to implementing the system life cycle. In this includes the pre-definition of specific deliverables that are created and completed by a project team to develop

This model is very famous model one in system development methodology. It is also referred to as a linear-sequential life cycle model. This method seen as flowing down thorough several steps, each steps or phases have different goals. Each phase is completed for next one started and there is no turning back or go back to previous phase. The oldest model for software engineering.

Advantages:
• The waterfall model is very simple and very easy to understand and use.
• It’s more comfortable to manage due to the stiffness of the model – each and each phase has particular outcome and review process.
• Waterfall model works well for smaller projects.
• In Waterfall model stages are processed and completed one at a time. Stages do not overlap.
• If a requirement is cannot be change for a project the waterfall model is good for that kind of projects.
• Complexity – good for inexperienced staffs
• End time is well understood because every phase have a milestone
• Quality is more important than cost or schedule.

Disadvantages:
• It’s not possible to go back and change something that was not

Agile method is used when time critical applications. Used in organizations that employ disciplined methods. Speed up or bypass one or more life cycle phases.

Advantages:
• agile helps to speed up the system development life cycle phases and diversion process steps that add little important value to the project.
• Usually agile methodologies encourage collaborative team approach.
• Agile methodology smooth flow of knowledge sharing
• Engages the stockholders continuously so that the new requirements are gathered faster and there is no scope for guess work by the teams
• Increases cohesion between the team to deliver on time
• Provides the last result of higher quality of the software deleivers and highly satisfied customer.
• Flexible documentation policies which save time.
• Saves time efforts and cost.

Disadvantages:
• In large software deliverables it is difficult to rate the effort required at the beginning of the software development life