. . . we have described optimal sizes of organizations needed to create large software systems on time and within budget -- SizeTheOrganization. The following pattern explains what to do for smaller systems (less than twenty-five thousand lines of code), when a product must still be created on time and within budget, but when rapid growth is not anticipated after the first release.
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When a smaller software project (less than twenty-five thousand lines of code) is overstaffed, communication overhead increases and talented individuals, who could produce the software entirely on their own, are bridled, their "horsepower" diminished.
We have said that organizational size affects the deliverable in a non-linear manner (SizeTheOrganization). We have also observed that communication overhead goes up as the square of the size, which means that the organization becomes less cohesive as the square of the size while the "horsepower" of the organization goes up only linearly.
The question then is, what organizational size works best for smaller software projects?
The answer depends on the individual(s) involved in the project. The productivity of a single individual can be higher than that of a collection of productive individuals. We have seen single-person developments generate 25KSLOC of deliverable code in 4 months (a craft interface for a telecommunication system); two-person developments do 135 KSLOC in 30 months. Many of these adhered faithfully to all stipulated reviews and verification steps.
Boehm [BibRef-Boehm1981] notes a 20-fold spread between the least and most effective developers. A telecommunications developer recently told me that "having the right expertise means the difference between being able to solve a problem in a half hour, and never being able to solve the problem at all."
(Note: Boehm quotes Grant and Stackman [BibRef-Grant1966] with a 26-fold spread, page 667.)
The result of using a SoloVirtuoso is an organization limited to small development. Though there is a singleton development role, other roles may be necessary to support marketing, toolsmithing, and other functions. The productivity of a suitably chosen singleton developer is enough to handle sizable projects; here, we establish 25KSLOC as a limit.
Therefore:
Do the entire design and implementation with one or two of your most effective developers.
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This pattern is not a "License to Hack." The work of SoloVirtuosos is still subject to technical reviews, validation, and verification at appropriate times in the development cycle — StandUpMeeting, EngageCustomers. This combines nicely with DevelopingInPairs.
See also ModerateTruckNumber, which raises concerns about the use of this pattern in risk-averse business.