For the Minneapolis/St. Paul Regional Area

Meeting Announcement
Thursday, 3 October, 2002
5:45-7:45 p.m. at The University of Minnesota
5:45 start for networking, 6:15 start for meeting
Electrical Engineering/Computer Science Bldg
Room EE/Csi 3-180
Minneapolis, MN

A map is available at
Check out the detailed map.

This Month's Meeting

Program Director: Pat Wegerson
Topic: Adding Bits of Precision to Use Cases

Speaker: Dave Gelperin, LiveSpecs Software

Networking begins at 5:45. Meeting begins at 6:15.

Light refreshments will be provided. Please remember to bring your parking ticket with you for free validation.

There will be a Software Improvement SIG meeting starting at 5:15 pm. The topic this month is "Practical Benchmarks, Part 2". Please check the TCQAA web site for additional information:

*Directions to The University of MN are included at the end of this message


Sometimes a few sentences or paragraphs are sufficient to describe usage, but sometimes more details are needed. Alistair Cockburn introduced the notion of "levels of precision in functional requirements". In a subsequent wiki discussion, he wrote about 1-bit through 6-bit precision corresponding to increasing information content. In his scheme for use cases, 1-bit precision names the goal, 2-bit adds the main scenario, 3-bit adds failure conditions, 4-bit adds failure actions, 5-bit adds data descriptions, and 6-bit adds user models.

In the spirit of agile methods and "just enough" written communication, user activities that are well understood could be marked by XP user stories (1.5-bits of precision?), while in cloudier areas (e.g., high complexity) some of the misunderstanding risk should be managed with descriptions of higher precision (i.e., more details). The project team should decide how much information to write for each user need. Sometimes this decision will be incremental as discussion reveals unanticipated complexity or misunderstanding.

This presentation will describe and illustrate by examples eight information candidates that you can use to increase the precision of your use cases. Each candidate can be used alone or in combination to supplement your current practices.

1. valid input alternatives

2. alternative system actions

3. embedded post-conditions

4. invariant case conditions

5. exception conditions - the unless clause

6. abstract conditions - e.g., request is valid

7. class constraints

8. dependencies between conditions

These candidates are included in a specification style called Precise Use Cases. A medium size example of this style for a library management system can be found at The paper upon which this presentation is based can also be found on


David ( is currently CTO & President of LiveSpecs Software in Minneapolis, MN. He has more than 35 years experience in software engineering with an emphasis on software quality, verification, and test (SQVT) including software process engineering.

Dave has been a SQVT consultant/mentor and instructor (20 yrs), quality support manager (5 yrs), verification lead (2 yrs), project lead (2 yrs), and programmer (5 yrs). He has consulted for both commercial and in-house software development organizations.

Dave cofounded Software Quality Engineering (, -- the leading provider of software quality information, worldwide -- in 1986 and catalyzed the launch of STQE (Software Test and Quality Engineering) magazine.

In addition, Dave chaired the development of both ANSI/IEEE standards on software testing - 829 on software test documentation and 1008 on software unit testing.

Dave is chief architect of:

1. the LiveSpecs Reference Model for Requirements Activities

2. the Better Requirements Platform(tm) & Product Explorer(tm)

3. Precise Usage Models(tm) and Precise Use Cases(tm)

4. a Testability Support model

5. High-Impact (tm) technical reviews

6. the Systematic Test & Evaluation Process (STEP (tm)) test methodology and

7. the Unique Cause & Pre-emptive Debugging test strategies.

David received a Ph.D. (1973) and MS (1970) in Computer Science from the Ohio State University, after majoring in math at Carleton College (1964)

Twin-SPIN Mission Statement

The Twin-SPIN software process improvement network (SPIN) is a regional organization established in January of 1996 as a forum for the free and open exchange of software process improvement experiences and ideas. Representatives from industry, government, academia, other professional organizations, and consultants are welcome to participate. Our mission is to help sustain commitment and enhance skills in the area of software process improvement through an active program of networking and mutual support. The organization strives to serve as a source of educational and experiential information for its members, other SPIN organizations, and the general community of software professionals.
May 1996

Meetings are normally held on the 1st Thursday of each month from 5:45-7:45 p.m. Twin-SPIN is a non-profit organization.

Twin-SPIN Meeting Sponsors

The University of Minnesota provides our meeting room and covers additional meeting expenses (i.e. parking, food) beyond the corporate sponsorship program.

The cost of a corporate sponsorship is $500, $200, or $100 per year. The money is used to provide refreshments for the meeting and various Twin-SPIN expenses. If your company is willing to sponsor Twin-SPIN all the information you need is on our University of Minnesota web site at , or contact Paul Kraska (612.823.6217).

Facility Sponsor

University of Minnesota - facility sponsor and underwriter for losses

$500 Sponsors

$200 Sponsors
Guidant Corporation, Software Engineering Department


$100 Sponsors
Analysts International
Armstrong Consulting
Benchmark QA
Goodrich Corporation, Sensor Systems
HighJump Software
Process Assessment, Consulting, and Training, LLC
Quality Software Technologies
Spherion Technology Architects
Third Wave Partnership LLC
United Defense
Wisesoft - web page sponsor

Twin-SPIN Meeting Program Managers and Topics

Month Program Manager Topic
January 2002 Ron Carlson Do's and Don'ts of SPI
February 2002 Dick Hedger Risks in Projects Using New Technologies
March 2002 Dick Hedger What is Excellence?
April 2002 Bill Gilbreath Lean Programming
May 2002 Dick Hedger SEI Presentations
June 2002 Dick Bland Software Architecture

October 2002 Pat Wegerson Requirements & Analysis


This month will be another very interesting and informative meeting, and if you know someone who might be interested in attending, don't hesitate to let them know what we are doing. Bring a friend to our meeting! Hope to see you there!

Paul W. Kraska PhD


Please visit our web site for directions or check out these maps:

See more detail in the "Close up view" at