1. Why software development difficult/different MIS,
lack of visualization: moving targets,
between se. communications, specification: ph1 report
Design: 2 levels: Architecture/high-level: modules/classes and detail/low-level design: alg+data struct (=program)
modules + comm; ds + logic/alg: each module
alg, math: difference equation: discrete version of differential eq/ math/modeling
Coding/implementation phase: understandable, clean logic, swimming and integration: deliver prod
Testing + integration
Maintenance: customer
SQA: system quality assurance team Toyota ()
Sys an>plan>design….
pros and cons:
quality, documentation, strict discipline; SQA
Cons: time/$ consuming; lack of comm; big overall risk; miss target

2. Software quality: most important: meet spec; other general ones: user friendly, efficiency, robustness, reliability, support
Rapid prototyping: quickly build summarizations reflect main func in order to communicate with clients/peers embedded in wf model
pros: better comm; better response/feedback
cons: invite more moving targets,
Wf+rp
Evolution: simplecomplex: system having ind. components
partition system into many builds:
Ccny mis: std + fac + lib + funding 2yrs
std(water fall+ proto): 8 months stop reduce risk
Pros: reduce overall risk,
Cons: fatal blow—hard to integrate, have to redo design/coding
Spiral model: military huge system
water fall + risk analysis at the end of each phase, Bayesian reasoning example
Pros: safety ; cons: very expensive
Pros and cons of these models