Chapter 16 – Software reuse. The objectives of this chapter are to introduce software reuse and to describe approaches to system development based on large-scale system reuse. When you have read this chapter, you will: understand the benefits and problems of reusing software when developing new systems; understand the concept of an application framework as a set of reusable objects and how frameworks can be used in application development. | Chapter 16 – Software Reuse Lecture 1 1 Chapter 16 Software reuse Topics covered The reuse landscape Application frameworks Software product lines COTS product reuse Chapter 16 Software reuse 2 Software reuse In most engineering disciplines, systems are designed by composing existing components that have been used in other systems. Software engineering has been more focused on original development but it is now recognised that to achieve better software, more quickly and at lower cost, we need a design process that is based on systematic software reuse. There has been a major switch to reuse-based development over the past 10 years. Reuse-based software engineering Application system reuse The whole of an application system may be reused either by incorporating it without change into other systems (COTS reuse) or by developing application families. Component reuse Components of an application from sub-systems to single objects may be reused. Covered in Chapter 17. Object and function | Chapter 16 – Software Reuse Lecture 1 1 Chapter 16 Software reuse Topics covered The reuse landscape Application frameworks Software product lines COTS product reuse Chapter 16 Software reuse 2 Software reuse In most engineering disciplines, systems are designed by composing existing components that have been used in other systems. Software engineering has been more focused on original development but it is now recognised that to achieve better software, more quickly and at lower cost, we need a design process that is based on systematic software reuse. There has been a major switch to reuse-based development over the past 10 years. Reuse-based software engineering Application system reuse The whole of an application system may be reused either by incorporating it without change into other systems (COTS reuse) or by developing application families. Component reuse Components of an application from sub-systems to single objects may be reused. Covered in Chapter 17. Object and function reuse Software components that implement a single well-defined object or function may be reused. Benefits of software reuse Benefit Explanation Increased dependability Reused software, which has been tried and tested in working systems, should be more dependable than new software. Its design and implementation faults should have been found and fixed. Reduced process risk The cost of existing software is already known, whereas the costs of development are always a matter of judgment. This is an important factor for project management because it reduces the margin of error in project cost estimation. This is particularly true when relatively large software components such as subsystems are reused. Effective use of specialists Instead of doing the same work over and over again, application specialists can develop reusable software that encapsulates their knowledge. 5 Chapter 16 Software reuse 5 Benefits of software reuse Benefit Explanation Standards compliance Some standards, such as .
