Chapter 9 – Software Evolution. In this chapter, the following content will be discussed: Measurement and quality assessment, framework for product metrics, metrics for requirements model, metric for design model. | Chapter 9 – Software Evolution Chapter 9 Software Evolution 1 30/10/2014 Topics covered Evolution processes Legacy systems Software maintenance Chapter 9 Software Evolution 2 30/10/2014 Software change Software change is inevitable New requirements emerge when the software is used; The business environment changes; Errors must be repaired; New computers and equipment is added to the system; The performance or reliability of the system may have to be improved. A key problem for all organizations is implementing and managing change to their existing software systems. Chapter 9 Software Evolution 3 30/10/2014 Importance of evolution Organisations have huge investments in their software systems - they are critical business assets. To maintain the value of these assets to the business, they must be changed and updated. The majority of the software budget in large companies is devoted to changing and evolving existing software rather than developing new software. Chapter 9 Software Evolution 4 30/10/2014 A spiral model of development and evolution Chapter 9 Software Evolution 5 30/10/2014 Evolution and servicing Chapter 9 Software Evolution 6 30/10/2014 Evolution and servicing Evolution The stage in a software system’s life cycle where it is in operational use and is evolving as new requirements are proposed and implemented in the system. Servicing At this stage, the software remains useful but the only changes made are those required to keep it operational . bug fixes and changes to reflect changes in the software’s environment. No new functionality is added. Phase-out The software may still be used but no further changes are made to it. Chapter 9 Software Evolution 7 30/10/2014 Evolution processes Chapter 9 Software Evolution 8 30/10/2014 Evolution processes Software evolution processes depend on The type of software being maintained; The development processes used; The skills and experience of the people involved. Proposals for change are the driver for system . | Chapter 9 – Software Evolution Chapter 9 Software Evolution 1 30/10/2014 Topics covered Evolution processes Legacy systems Software maintenance Chapter 9 Software Evolution 2 30/10/2014 Software change Software change is inevitable New requirements emerge when the software is used; The business environment changes; Errors must be repaired; New computers and equipment is added to the system; The performance or reliability of the system may have to be improved. A key problem for all organizations is implementing and managing change to their existing software systems. Chapter 9 Software Evolution 3 30/10/2014 Importance of evolution Organisations have huge investments in their software systems - they are critical business assets. To maintain the value of these assets to the business, they must be changed and updated. The majority of the software budget in large companies is devoted to changing and evolving existing software rather than developing new software. Chapter 9 Software .
