7/17/25About 347 words
Plan-based Development
- A plan-driven approach to software engineering is based around separate development stages with the outputs to be produced at each of these stages planned in advance.
- Not necessarily waterfall model. Incremental development is possible.
- Iteration occurs within activities.
Agile Development
- Specification, design, implementation and testing are inter-leaved.
- The outputs from the development process are decided through a process of negotiation during the software development process.
Agile Methods
- Focus on code rather than the design.
- Are based on an iterative approach to software development.
- Are intended to deliver working software quickly and evolve this quickly to meet changing requirements.
- To reduce overheads in the software process and to be able to respond to changing quickly.
- Without excessive rework.
Principle of Agile Methods
| Principle | Description |
|---|---|
| Customer Involvement | Customers should be closely involved throughout the development process to provide and prioritize new system requirements and to evaluate the iterations of the system. |
| Incremental Delivery | The software is developed in increments with the customer specifying the requirements to be included in each increment. |
| People Not Process | The skills of the development team should be recognized and exploited. Team members should be left to develop their own way of working without prescriptive processes. |
| Enhance Change | Except the system requirements to change and so design the system to accommodate these changes. |
| Maintain Simplicity | Focus on simplicity in both the software being developed and in the development process. Actively work to eliminate complexity from the system. |
Agile Method Applicability
- Product development where a software company is developing a small or medium-size product for sale.
- Custom system development within an organization, where there is a clear commitment from the customer to become involved in the development process and where there are few external rules and regulations that affect the software.