Joe's Jottings
Jottings Number 6, by Joe Podolsky:
From: uunet!opnmail3.corp.hp.com!PODOLSKY_JOE/HP0000_02
Date: Tue, 15 Nov 94 14:14:00 -0800
Capers Jones is a well-known software productivity and quality guru who writes a column for the IEEE Computer magazine, entitled "Software Challenges." In the November 1994 issue, Jones talks about "geriatric software." He says that a recent study of 1.8 million software programs showed that about half are working on modifying existing software. When analyzed by the language of the software, the maintenance percentages go way up, for example, 84% for software written in Assembly language and 67% for software written in COBOL. Jones suggests that maintenance is a process that can be managed and dramatically improved. Jones proposes a metric called a "maintenance assignment scope" which is calculated by dividing the number of maintenance programmers into the size of the code they are maintaining. Jones says his data shows that the U.S. average maintenance assignment scope is about 500 function points (about 5000 lines of source code, depending on language). The range, however, is dramatic. Jones says that the most efficient organizations can exceed maintenance assignment scopes of 2000 function points. He cites an insurance company that tripled its maintenance assignment scope over five years, driving its budget for software maintenance from over 60% to under 20%. I don't know of any software organization in HP, either product line or informations systems group, that keeps metrics like this, and without such data, improving the maintenance process is dependent on the varying energy and enthusiasm of the project teams. And, perhaps equally scary, we may not be learning the lessons we need so that the new software we're writing (or acquiring from vendors) will be substantially easier to maintain than our existing portfolio. Do you know of any effective software maintenance activities in HP? Regards, Joe