1.
Maintenance Framework
Steve Chenoweth
CSSE 375, Rose-Hulman
Based on Don Bagert’s 2006 Lecture
Ref M 2

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Today
• Turn in last Friday’s quiz, if not already…
• Any Q on “one minute talk” for Thurs (&
turn-in on Angel Wed night)?
• Finish off yesterday’s stuff – Intro to
Maint & Constr
• Today’s topic – this
• Maybe just a start on Thursday’s topic –
Software Change

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Definition
• A framework is a set of ideas, conditions or
assumptions that determines how something
will be approached, perceived on understood

4.
Discussion: Who and what
need to be involved in
software maintenance?

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Software Maintenance
Framework Components
• User Requirements
• Organizational Environment
• Operational Environment
• Maintenance Process
• Software Product
• Maintenance Personnel

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User Requirements
• Requests for additional features
– Usually – Wait for next release
– Specials for key customers or submarkets
• Correction of defects (bugs)
– Fix now
– Wait for next release
• Other support (e.g. training, help desk)
– Should developers take a turn at the help desk?

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Organizational Environment
• Change in Policies
– FDA – 13485 compliance
– Banking, Insurance, …
• Competition
– They announce the iPhone
• Add - Internal management changes
– Your group is merged with another group, under
their old management

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Operational Environment
• New Platform
– Hardware
– Operating System
– Third Party Software
• Nasty scenario – One of the components you
use forces you to do an expensive upgrade
• Nastier – That upgrade won’t work with other
components you have to use

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Maintenance Process
• Capturing requirements / maintenance requests
• Investigating and prioritizing those requests – Creativity
and undocumented assumptions
• Variation in programming practice – Coding and
documentation standards
• Paradigm shift – Programs with “old structures” that are
now indecipherable
• Dead paradigms for living systems – Legacy code issues –
Fixed Point Theorem for Info Systems
• Error detection and correction – Finding the root cause of
software errors… growing cost as the system is developed –
and used! 

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Maintenance Process - Error
detection and correction

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Software Product
• Application domain issues – domains mature
• Documentation quality – causes support issues
• Code flexibility – No clear standards for code
changes (vs the rest of engineering)
• Code complexity – keeps getting worse
• Program structure – ditto, unless refactored
• Product quality – kinda like entropy

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Maintenance Personnel
• Staff Turnover – A total killer of maintenance
capability
– Which often means, key people can never leave!
• Application Domain Expertise – A critical
intellectual property
• Working Practices – The “attitude” thing. A
long-term focus is required of the people

13.
Discussion:
What
relations and
interactions
with the
product are
the most
important in
maintenance?