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(CSC-1986) Using Theoretical S-Curve to Forecast Project Duration Considering Past Performance

Primary Author: Mr Rafael Gonalves Monteiro
Co-Author(s): Mr Vinicius Oliveira Daher

Audience Focus: Intermediate
Application Type: Research
Venue: 2015 AACE International Annual Meeting, Las Vegas, NV, USA

Abstract: Project controls tools are considered keystones to project managers regarding costs, schedule and risk management. Projects’ environments are really challenging and unsettled; therefore, procedures and standards for estimating, planning, controlling and forecasting are truly welcome. Notwithstanding these procedures being crucial, it is common that Owners fail to have contemporaneous and consistent data from Contractors. Aiming to help Owners (and even Contractors) to forecast the total duration of a project, this paper explores how to use a mathematical equation of a general S-curve to predict project duration at completion. This paper differs from previous works because the past performance (physical progress) is used to fit a theoretical S-curve using the method of (weighted) least squares. Also, is neither mandatory to know the remaining quantities to be executed nor the original planned curve (or value), since no scope change had happened and the actual physical progress reflected reality. Finally, some examples will be presented showing how to use this procedure and how easy it is to implement using electronic spreadsheets, in spite of the mathematic behind it.