From outputs to outcomes: Meeting a threshold of short-term project management success as a necessary condition for achieving long-term impact

• This paper clarifies conflicting perspectives on the relationship between project management success and project success. • It shows that meeting a project management success threshold is a necessary (though insufficient) condition for achieving project success. • Among project management success measures, quality requires a higher threshold than schedule or cost targets. • The paper advances the Outputs–Outcomes–Value–Impact model by uncovering the non-linear relationship between efficient output delivery and effective outcome realization. The literature is conflicted as to whether achieving short-term project management success (e.g., delivering project outputs on time and within budget) is necessary for attaining long-term project success (e.g., benefits realization and project impact). This research examines the relationship between project management success and project success using data from two studies: a survey of 198 U.S. projects and an analysis of 154 World Bank projects. Results suggest that meeting a project management success threshold is a necessary, though insufficient, condition for attaining long-term project success; in other words, if a project management success threshold is not met (e.g., poor quality of the project’s outputs), long-term project success is unlikely to be attained. Further, among the project management success measures, quality was found to require a higher threshold than schedule and cost. This means that a project can still achieve long-term project success despite some schedule delays and cost overruns, but this is unlikely to occur if there are major quality issues with its outputs. Overall, this paper clarifies conflicting perspectives in the literature regarding the relationship between project management success and project success, reveals the non-linear nature of this relationship, and supports project leaders (e.g., project managers and project owners) in making better project decisions.