Maintenance Maintenance FrameworkFramework

Maintenance Maintenance FrameworkFramework

Steve ChenowethSteve ChenowethCSSE 375, Rose-HulmanCSSE 375, Rose-Hulman

Based on Don Bagert’s 2006 LectureBased on Don Bagert’s 2006 LectureRef M 2Ref 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

Discussion: Who and Discussion: Who and what need to be what need to be

involved in software involved in software maintenance?maintenance?

Discussion: Who and Discussion: Who and what need to be what need to be

involved in software involved in software maintenance?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

Discussion: Discussion: What What

relations and relations and interactions interactions

with the with the product are product are

the most the most important in important in maintenancemaintenance

??

Discussion: Discussion: What What

relations and relations and interactions interactions

with the with the product are product are

the most the most important in important in maintenancemaintenance

??