ITEC 370
Lecture 22
Maintenance
Review
• Questions?
• Project update on F, next F give prototype
demonstration
• Interface testing
– Checklist of design features
– Users
Maintenance
Objectives
• Maintenance
– What do you do once it is delivered???
Maintenance
Fin
• Congrats, you just delivered your product
Maintenance
Now what
• Decide on the style of maintenance you
want to follow
• Reactive
• Proactive
Maintenance
Reactive
• Status quo and keeping it
• Only react when a client requests a fix
– Corrective maintenance
• Benefits
– Less attention required to details
– Retraining less of an issue
• Downsides
– Not good for publicity of product
– Miss opportunities
Maintenance
Example
• DGL – software created for my dissertation
• Used by NIST / VT on a daily basis for 5+
years
• No new major development for 5+ years
• Bug fixes when a particular problem
occurs with an application
• No new adopters
Maintenance
When
• Good for when clients are not apt to
change
– Expensive retraining
• Manufacturing lines
• Call centers
• You don’t have the resources to do
anymore than is necessary
• Buggy updates are bad…
Maintenance
Active
• Anticipate what is coming down the road
• New software versions and compatibility
– Preventative maintenance
• Competitors products
• Improve on what you currently have
– Graphics card drivers
Maintenance
iOS
software
• App store provides millions of users a
chance to find software that smaller
developers probably wouldn’t ever have
been able to put in front of users
– AngryBirds anyone?
• Requires a lengthy “validation” by Apple
beforehand
• Apple changes their platform constantly
Maintenance
Betting on
maintenanc
e
• World of Warcraft
– November 23rd 2004
• Team Fortress 2
– Since 2007, would you like a hat with that?
– Halloween themed levels
Maintenance
Numbers
• Typically
– 25% Adaptive
– 20% Corrective
– 55% Preventative
• In other words, time moves on and so
must your software
Maintenance
Lehman’s
laws
•
•
•
•
•
•
Continuing change
Increasing complexity
Conservation of familiarity
Continuing growth
Declining quality
Feedback system
Maintenance
Environmen
ts
• Remember the user’s environment may be
different than what you use
• Remember your environment’s quirks
• Remember staging is your best friend
Maintenance
Update
testing
•
•
•
•
Remember, change causes issues
Deleting/corrupting user data
Clean install
Over-write information
– Do you force an overwrite?
– Only update the pieces needed?
Maintenance
Review
• Reactive
• Active
Maintenance