Cleanroom Software Engineering

By: David Golke

Introduction Architecture Specification

◦ Requirements Analysis◦ Function Specification◦ Usage Specification◦ Increment Planning

Topic Overview

Architecture Specification◦ Software Reengineering, Increment Design,

Correctness Verification◦ Usage Modeling and Test Planning◦ Statistical Testing and Certification

Examples Projects Conclusion Questions?

Topic Overview (continued)

Harlan Mills and colleagues from IBM Where does the name come from? Defect prevention Quality Control

Introduction

Architecture Specification

Figure out what the customer wants As usual, subject to change We need requirements laid out in a way for

future defect prevention

Requirements Analysis

Break down requirements (easily verifiable) Tagging Used in later steps

◦ With Box Structure Method◦ For Function and Usage Specification◦ For Increment Planning

Requirements Analysis

Tagging

Requirements Analysis

Both come directly after Requirements Analysis

How the system will function How the users will interact with the system

◦ Who are users◦ Different environments◦ Usage scenarios

Function and Usage Specification

Box Structure Development Method◦ Black box◦ State box◦ Clear box

Differ from◦ Black box◦ Grey box◦ White box

Function Specification

Stimuli Response Keep track of all previous input/stimuli Also subject to change throughout the

project Product: “Function Specification Document”

Function Specification

Created from tagged requirements and Function Specification◦ Aren’t these concurrent?

Used to make sure Function Specification is complete and accurate.

Usage Specification

Uses◦ How much testing needs to be done◦ Analyzing probabilities of failures◦ How many resources are needed◦ Along with Function Specification will later be

used to determine probabilities of failure.

Usage Specification

Released in pieces Must plan how “pieces” are released “Increment Construction Plan”

◦ Subject to change Once again uses previously produced

documents to produce this document

Increment Specification

Subject to change (as always) Uses of increments

◦ Identify failures◦ form final product

Increments are made from previously discussed box structures

Increment Specification

Increment Specification

Reusing old code◦ Must meet cleanroom requirements

Was it developed using cleanroom? Must get it certified How much will this cost? Figure out functionality

◦ create new reengineered software to our needs

Software Reengineering

Follow through of the plan from Increment Specification

Use plan to produce design and code Use Increment Construction Plan to do this

Increment Design

Must be correct Mathematical verification Statistical testing

Correctness Verification

Used together with Test Planning Usage model

◦ Set up every possible way the program can be used

◦ Reason for input/stimuli/usage history◦ Determine all possible “usages”

Usage Modeling

Uses usage model Must be able to produce statistics This along with Usage Modeling will be used

later for testing and certification

Test Planning

Depends on previous correctness Final step Certification may be different in different

cases/projects Makes use of documents created in previous

steps

Statistical Testing and Certification

Example Projects

Unique software practice Build off of previous steps Must maintain correctness throughout steps Probably only used when the system cannot

afford failures/defects

Conclusion

Questions?

Prowell, Stacy J., Carmen J. Trammell, Richard C. Linger, and Jesse H. Poore. Cleanroom Software Engineering: Technology and Process. Reading, MA: Addison-Wesley, 1999. Print.

Becker, Shirley A., and James A. Whittaker. Cleanroom Software Engineering Practices. Harrisburg, PA: Idea Group Pub., 1997. Print.

Mills, Harlan D.; Dyer, M.; and Linger, R. C., "Cleanroom Software Engineering" (1987). The Harlan D. Mills Collection. http://trace.tennessee.edu/utk_harlan/18

R. C. Linger "Cleanroom Software Engineering for Zero-Defect Software", Proc., 15th Int. Conf. on Software Eng., pp.2 -13 1993 from http://cs.txstate.edu/~rp31/papersSP/LingerCleanroom1993.pdf

Garbett, S. P. (2003). Cleanroom software engineering. Dr.Dobb's Journal, 28(8), 24-28. Retrieved from http://www.drdobbs.com/architecture-and-design/cleanroom-software-engineering/184405405

References