- S-Type systems have a fixed specification, correctness and clear success criteria
- E-Type systems are real world systems where user satisfaction is the only success criteria and cannot be specified in advance as each intervention/innovation becomes part of the system and changes it
- P-Type systems are somewhere in the middle between E and S
Ken Thompson (aka The BumbleBee) blogs about bioteams, virtual collaboration and business simulation at www.bioteams.com.