On the edge-analysis of transactions and computers

The authors describe how they used transaction analysis to help develop the software for the US National Aeronautics and Space Administration´s Freedom space station. The method consists of breaking the task down into a series of smaller tasks, and writing for each of these a competency statement that specifies what must be done (the skill of the task), how well it should be done (the qualitative and quantitative level of performance), what is needed to execute the skill (the conditions), and what must be known to execute the skill (the knowledge base). Application of this technique to the software requirements design for the Freedom space station resulted in a complete software specification that described what must be done. An additional benefit of using transaction analysis is that if the description and competency statement for an atomistic task is the same for two different branches of a breakdown, a good chance exists that one piece of computer code can perform both jobs.<>