Software Maintenance

Question 1

Maintenance why need

Answer 1

20% dev, 80% maintain

Question 2

What is Maintenance Prediction and Prediction Model

Answer 2

predict can maintain or not
predict costs
predict sys changes

Question 3

Lehman’s Laws

Answer 3

continuing change
increasing complexity
declining quality
organisational stability

Question 4

Key Issues in Maintenance

Answer 4

technical
dumb homies
no tests
ugly code
management
sad people
bad contracts
cost

Question 5

What are COTS
Components?

Answer 5

Usually complete
application systems that
offer an API (Application
Programming Interface).

Question 6

Key
Benefits of COTS

Answer 6

faster, cheaper

Question 7

Design Decisions with COTS

Answer 7

which is best for me
how interface
what part of the whole COTS do we actually need

Question 8

Maintenance Considerations with COTS

Answer 8

advertised good, but actl shit
cant interface
no control over evolution
no support (e.g. bybit)

Question 9

What is System Re-Engineering?

Answer 9

rewrite, redocument etc

Question 10

When is System Re-Engineering applicable?

Answer 10

• Where some (but not all) sub-systems of a
  larger system require frequent maintenance.

Question 11

Re-Engineering Process

Answer 11

(skim, ish)
► Reverse Engineering
v Analyse software to identify components and their relationships
v Create representation at higher levels of abstraction e.g. documentation,
UML diagrams, ER diagrams
► Forward Engineering
v Programme structure improvement
v Programme modularisation
v Data re-engineering

Question 12

Re-Engineering Cost Factors

Answer 12

quality
tool support
how many pros in the building