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Lecture Software construction - Lecture 22: Software change, evolution and maintenance - Part II

Lecture Software construction - Lecture 22: Software change, evolution and maintenance - Part II. This chapter presents the following content: Software maintenance, maintenance examples, the maintenance process, why is maintenance inefficient? Maintenance echniques, user interface distribution,. | Software Construction Lecture 22 Software Change, Evolution and Maintenance Part II Software Maintenance Software maintenance is the general process of changing a system after it has been diverted. The change may be simple changes to correct coding errors, more extensive changes to correct design errors or significant enhancement to correct specification error or accommodate new requirements. Maintenance Examples Y2K many, many systems had to be updated language analyzers (find where changes need to be made) Anti-Virus Software don't usually have to update software, but must send virus definitions Maintenance Examples (cont’d) Operating System Patching Microsoft, Apple, Linux/Unix OS is core to use of computer, so it must be constantly maintained Commercial Software in General customers need to be informed of updates updates have to be easily available - web is good tool The Maintenance Process Maintenance process vary considerably depending on the types of software being . | Software Construction Lecture 22 Software Change, Evolution and Maintenance Part II Software Maintenance Software maintenance is the general process of changing a system after it has been diverted. The change may be simple changes to correct coding errors, more extensive changes to correct design errors or significant enhancement to correct specification error or accommodate new requirements. Maintenance Examples Y2K many, many systems had to be updated language analyzers (find where changes need to be made) Anti-Virus Software don't usually have to update software, but must send virus definitions Maintenance Examples (cont’d) Operating System Patching Microsoft, Apple, Linux/Unix OS is core to use of computer, so it must be constantly maintained Commercial Software in General customers need to be informed of updates updates have to be easily available - web is good tool The Maintenance Process Maintenance process vary considerably depending on the types of software being maintained, the development processes used in an organization and people involved in the process. Change requests Impact analysis Release planning Change implementation System release Fault repair Flat form adaptation System enhancement Overview of the Maintenance Process .[SOM2004] Why is Maintenance Inefficient? Factors adversely effect maintenance Lack of models or ignorance of available models (73%) Lack of documentation (67.6%) Lack of time to update existing documentation (54.1%) Other factors (1994 study) Quality of original application Documentation quality Rotation of maintenance people Why is Maintenance Inefficient? (cont’d) More factors (Yip ’95 study) Lack of human resources Different programming styles conflict Lack of documentation and tools Bad maintenance management Documentation policy Turnover Maintenance Techniques Architectural Evolution There is a need to convert many legacy systems from a centralised architecture to a client-server architecture Change drivers Hardware .