Deck 28: Formal Modeling and Verification

Question 1

What are the advantages of using a formal language to write a software specification?

Answer 1

The formal syntax of a specification language enables requirements or design to be interpreted in only one way,eliminating ambiguity that often occurs when a natural language (e.g. ,English)or a graphical notation (e.g. ,UML)must be interpreted by a reader.The descriptive facilities of set theory and logic notation enable a clear statement of requirements.To be consistent,requirements stated in one place in a specification should not be contradicted in another place.
Final Exam Question

Question 2

Describe the process of writing a formal specification for some system function.

Answer 2

-Define a system state in terms of the objects manipulated by the function
-Using a simple mathematical function as an example,define the data invariant by writing data relations that will not change during the execution of the function
-Write the precondition and postcondition for the function using mathematical notation to show the system state before and after the

Question 3

What are the unique characteristics of cleanroom software engineering techniques?

Answer 3

-Make extensive use of statistical quality control
-Verify design specification using mathematically-based correctness proofs
-Rely heavily on statistical use testing to uncover high impact errors

Question 4

List the steps required for certification in cleanroom software engineering.