People Factors in Software Management: Lessons From Comparing Agile and Plan-Driven Methods

R we have been studying the characteristics of agile and plan-driven methods to provide guidance in balancing the agility and discipline required for successful software acquisitions or developments [1]. One of the most significant results of our analysis was the realization that, while methodologies, management techniques, and technical approaches are valuable, the most critical success factors are much more likely to be in the realm of people factors. We believe that the agilists have it right in valuing individuals and interactions over processes and tools [2]. However, they are not the first to emphasize this. There is a long list of wake-up calls: Weinberg’s 1971 “Psychology of Computer Programming” [3], the Scandinavian participatory design movement [4], DeMarco and Lister’s 1987 “Peopleware” [5], and Curtis’ studies of people factors [6] and development of the People Capability Maturity Model [7]. There is also a wealth of corroborative evidence that people factors dominate other software cost and quality drivers. These include the 1986 Grant-Sackman experiments showing 26:1 the variations in people’s performance [8], and the 1981 and 2000 Constructive Cost Model (COCOMO) and COCOMO II cost model calibrations showing 10:1 the effects of personnel capability, experience, and continuity [9, 10]. However, the agilists may finally provide a critical mass of voices amplifying this message. In this article, we discuss five areas where we believe significant progress can be made: staffing, culture, values, communications, and expectations management.