The methodology works!

Years earlier, while working in a group dedicated to unraveling the complexities of operating sys­tems, I had worked with Henry Stambler, a former IBM-er who had been recruited by CDC. Henry was intrigued by my database management concepts.

In 1967, CDC had provided the hardware for a very innovative project at Case Western Reserve University; Dr. Larry Weed’s Problem Oriented Medical Information Systems (PROMIS) project. They were using touch screen terminals (Digis­cribe) to enter and retrieve medical records at patients’ bedsides. The PROMIS project moved, lock, stock and barrel, to the University of Vermont in Burlington, Vermont in 1969. Henry Stambler left CDC a few years later and joined the PROMIS project, where he designed their file system. The history of PROMIS is available here.

Henry Stambler persuaded the PROMIS project management to invite me in to tell them about my database management concepts. I went to visit the project for a couple of weeks. They liked my con­cepts and invited me to join them.

While I was in Vermont I also made some presentations on my problem-solving methodology. Every­one on the project attended. The software people rejected the ideas out of hand, they felt they didn’t need that sort of mothering. Ironically, it was the hardware engineers that wanted to try it. So I spent a few days with them using decision tables to solve some hardware design problems. They took to the methodology like the proverbial ducks to water.

The software group had been working together for some years and had a huge investment in their solution. I realized that changing horses in this rapidly moving stream wouldn’t work, so I thanked them for the offer to join them but did not accept the offer. (I went home to Minnesota with a huge jug of maple syrup.)

Somewhere along the line the hardware engineers must have per­suaded the software people to try decision tables. From page 32 of the history referenced above:

…Henry Beitz, a CDC consultant, convinced us that an unlimited entry decision table could be used as the basis for demonstrating an understanding of a problem and also as the funda­mental design document. Decision tables were used to design and test the interface among hardware and software modules.

The run-time environment developed to support PPL (described in the next section) was de­fined in 17 decision tables and 78 rules. The definition of the polled multi-drop protocol to connect the high-speed terminals to the CPU was a set of 12 decision tables with a total of 77 rules. The protocol was used by Varian Data Machines, by MEGADATA, and by PROMIS Labo­ratory. When the hardware was delivered and the terminals were connected, the system operated correctly the first time it was tried (my emphasis).

The report referenced above was written nearly 10 years after my visit to the PROMIS project. I had no idea that the software group had embraced decision tables so enthusiastically.