CSE584: Software Engineering Lecture 3: Requirements & Specification (B)
Last week & this week
Before that…
Two NASA failures: each over $100 million http://www.nasa.gov/newsinfo/marsreports.html
Specification errors?
Specifications thread
State machines
Classic examples
A snippet of cruise control
More cruise control
Statecharts: “review”
Key idea: hierarchy
Parallel AND-machines
A few statechart features
Variants on statecharts
PPT Slide
Sample transitions
Leap of faith
Question
Standard answers include
An alternative: model checking
State Transition Graph
Example
A computation tree
Temporal formulae
Mutual exclusion example
How does model checking work? (in brief!)
Symbolic model checking
Binary decision diagrams (BDDs)
BDD-based model checking
BDD-based successes in HW
Software model checking
Why might it fail?
Our approach at UW—try it!
TCAS
TCAS specification
TCAS—high-level structure
Using SMV
Iterative process
Use of non-determinism
Translating RSML to SMV
State encoding
Events
Non-deterministic transitions
Checking properties
Property checking
Disclaimer
Deterministic transitions
Function consistency
Display_Model_Goal
Output agreement
Output agreement check
Limitations
Whence formulae?
What about infinite state?
Model checking wrap up
I know this was quick
It’s show time!
Good night
Email: notkin@cs.washington.edu
Home Page: http://www.cs.washington.edu/education/courses/584
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