Communication to the Editor—The Use of Subjective Probability Estimates in Assessing Project Completion Times

The conclusion from this analysis supports King's [King, W. R., T. A. Wilson. 1967. Subjective time estimates in critical path planning—A preliminary analysis. Management Sci.13(5, January) 307–320.] main point that there is little evidence of learning (i.e. improvement in the accuracy of estimates) in the period before work starts. There are, however, some differences. In this situation, more changes in estimates are made before work starts than reported by King. This is perhaps not surprising since King's analysis refers to new construction, which can perhaps be specified more clearly in advance, rather than the maintenance work which we are concerned.