Chief Programmer Team Update
- Posted on March 31, 2008 5:28:PM by Steve McConnell to 10x Software Development
- Technique, project management, productivity, Management, Team Organization, Chief Programmer Team, Articles
One spinoff from the 10x difference in programmer productivity was the Chief Programmer Team structure. The idea of the chief-programmer team was originally developed at IBM during the late 1960s (Baker 1972, Baker and Mills 1973). It was popularized by Fred Brooks in the Mythical Man-Month (Brooks 1975, 1995), in which Brooks referred to it as a surgical team. The two terms are interchangeable. I described the technique in my 1996 book Rapid Development, but I think we've learned some important lessons about the CPT structure since then.
Original Chief Programmer Team Project
The original chief programmer team project was conducted in the late 1960s. IBM commissioned to build an information retrieval system for the New York Times. The Chief Programmer on that project (the original Chief Programmer) was Harlan Mills, who created all the design and wrote all of the production code. He had eight other people arrayed around him in various support functions:
- A "backup programmer" serves as the chief programmer’s alter ego. The backup programmer supports the chief programmer as critic, research assistant, technical contact for outside groups, and backup-up chief.
- The "administrator" handles administrative matters such as money, people, space, and machines. The Chief has ultimate say about these matters, but the administrator frees the Chief from having to deal with them on a daily basis.
- The "toolsmith" is responsible for creating custom tools requested by the Chief . In today’s terminology, the toolsmith would be in charge of maintaining the build environment, creating scripts, etc.
- The team is rounded out by a "language lawyer" who supports the Chief by answering esoteric questions about the programming language the Chief is using.
Several of the support roles suggested in the original chief-programmer proposal are now regularly performed by nonprogrammers--by documentation specialists, test specialists, and program managers. Other tasks such as word processing and version control have been simplified so much by modern software tools that they no longer need to be performed by support personnel. And the internet has reduced the need for language lawyers--many questions can be answered via a quick search on the web.
Attempts to Replicate IBM’s Chief Programmer Team Results: Is 10x Good Enough?
On the original project, Harlan Mills personally wrote 83,000 lines of production code in one year. He wrote that code on a batch mode operating system. And on punch cards! Even when you divide the 83,000 lines of code by the nine people on the project, that’s 9,200 lines of code per staff year, which is still in the ballpark of acceptable productivity for similar kinds of projects 40 years later. With productivity like that under those circumstances you can see why the IBM project was heralded as one of the most successful projects of its time.
In the years since that project many organizations have tried to implement Chief Programmer teams, and few have been able to repeat IBM’s initial stunning success. The achilles heel of the Chief Programmer Team model is that for it to make sense to organize staff the way they were organized on the IBM project, the Chief Programmer has to be more productive than everyone else on the team put together. On the original IBM project, Harlan Mills was a near-genius programmer who was an expert software methodologist, talented writer, exceptionally self-disciplined, and highly motivated. When he decided to roll up his sleeves and write code, he had few peers. Think "Kent Beck of His Day" and you’d be pretty close. He was one of the rare individuals truly capable of doing more work than the eight other people on his team put together.
In a previous blog posting I discussed the fact that numerous studies have found 10-fold variations in productivity between the best and worst programmers with similar levels of experience. For the CPT model to work, the Chief Programmer doesn’t have to be 10x as productive as the worst programmer. He has to do the work of eight or nine people put together, which means he has to be 10x as productive as the average programmer, not 10x as productive as the worst. That’s a very tall order. If you assume the best programmer is 10x as productive as the worst, then the best will be only something like 2-3 as productive as the average programmer, and that isn’t good enough for the CPT model to pay off with a total project team of nine people.
Another factor is that, while numerous studies have found 10x differences among individuals, researchers have not found 10-fold differences among programmers working within the same organizations. Some research has found that good programmers tend to cluster within certain companies, average programmers tend to cluster within other companies, and so on (Mills 1983). So even if there’s a 10x difference industrywide, the difference you’d typically see within a given company is more like 3-5x from best to worst, which means the difference from best to average is more like 1.5x or 2x within any given company.
Bottom line: The Chief Programmer Team organization can make sense in the rare case in which you have a near genius on your staff--one that is dramatically more productive than the average programmer on your staff. But from I've seen there are far fewer near geniuses than there are near genius wannabees, and that limits the applicability of the technique.
Brooks, Frederick P., Jr. The Mythical Man-Month, Reading Massachusetts: Addison-Wesley, 1975.
Brooks, Frederick P., Jr. The Mythical Man-Month, Anniversary Edition, Reading Massachusetts: Addison-Wesley, 1995.
Baker, F. Terry. "Chief Programmer Team Management of Production Programming," IBM Systems Journal, vol. 11, no. 1, 1972, pp. 56-73.
Baker, F. Terry and Harlan D. Mills. "Chief Programmer Teams." Datamation, Volume 19, Number 12 (December 1973), pp. 58-61.
McConnell, Steve. Rapid Development. Microsoft Press, 1996.
Mills, Harlan D. Software Productivity, Boston, Massachusetts: Little, Brown, 1983.