August 21, 2009

Software Maintenance? Didn’t they teach you that in school?

Software Maintenance? Didn’t they teach you that in school?
You just graduated from school last week in Computer Science to be a developer, and it is you second week on your new “high paying” [ah!] entry level job. You boss just ask you to go and fix this bug that the customer just found, thinking it would be a good idea to get introduced to the software system that was written before you were born. Oh, and he want to know how long it will take to fix it. You tell him that you don’t know to fix other peoples code nor how long it would take. He ask, “Why not, didn’t they teach you that in school?

Purpose
The purpose of this blog is to identify tools, techniques, and methodologies to improve the peon programmer, like myself, ability to solve software maintenance problems.

Overview of Software Maintenance
Since the invention of “HelloWorld” there has been software maintenance. It has gone by different names, from debugging, operations and maintenance, operations & support, new features, etc. But purpose has stay the same, fix problems with existing code and/or add new features with out adding new problems.

E.B. Swanson[1] initially identified three categories of maintenance: corrective, adaptive, and perfective. These have since been updated and ISO/IEC 14764 presents:
• Corrective maintenance: Reactive modification of a software product performed after delivery to correct discovered problems.
• Adaptive maintenance: Modification of a software product performed after delivery to keep a software product usable in a changed or changing environment.
• Perfective maintenance: Modification of a software product after delivery to improve performance or maintainability.
• Preventive maintenance: Modification of a software product after delivery to detect and correct latent faults in the software product before they become effective faults.

Why should I learn to do software maintenance?
Have you ever had to read you own code from six month ago? Have you ever had to review someone else’s code? Have you had to read documentation about you favorite software, and discovered it is not up to date? Have you had to use freeware, and make modification? If so, you have done software maintenance.

Reference
1. http://en.wikipedia.org/wiki/Software_maintenance