Application Development Facility

Application Development Facility (ADF II) was a 4GL application package developed by IBM for use under IMS databases. It allowed a programmer to define a set of "rules", which, when combined with a simple to use screen painter, could be used to generate an IMS DC application.

The rules were divided into static and dynamic rules. The static rules defined the data objects that could be organised into a structure identical to the IMS database structure on which it was based. In its simplest form each data base segment would be converted into a separate transaction.

Data input could then be validated by the audit rules or dynamic rules. These were held on an IMS data base, so that ADF was actually written in ADF.

More complex transactions could be written by using exits coded in Cobol or PL/1. There was also a language that could be used to generate the dynamic rules on the ADF database.

By using exits in Cobol and PL/1, almost any level of complexity of IMS DC system could be developed using ADF. It had the added benefit that screens could be generated without any knowledge of MFS.

Standard ADF applications produced a series of free transactions that provided navigation from one transaction to the next via a concatenated key, and selection screens for lower segments in the hierarchy.

It was also possible to write the application almost entirely in either Cobol or PL/1 by defining it as a Special ADF application.

ADF was very popular in the 1980's in large IMS DB/DC environments as a quick development tool. Most installations used it to develop simple systems that required a low level of sophistication, and had a small budget. However some companies used it as their main tool for even the most complex on-line systems. It was at first heavily promoted by IBM, but a new version released in the mid 1980's was not purchased by many (if any) companies, mainly because it would have required some developement work on existing systems to implement it. Soon after that IBM withdrew support for it, which effectively sealed its fate.

ADF systems were still in use during the 1990's, but as far as I know none of them made it past the end of the century as it did not support an eight digit date.

An obscure piece of trivia is that the load modules that were generated by ADF all started with the characters MFC. I was told that this was because it had originally been develped for a company called the Municial Floor Company. (If this is an urban myth then I apologise for it as I would hate to mislead anyone).

In a world where there are stamp collectors and train spotters, I am sure someone will one day write a book on the history of computer languages and if so I do hope they will consider that ADF deserves its places in history.

(written my Roy Cropper)