Development of an Effort Estimation Model: A Case Study on Delivery Projects at a Leading IT Provider within the Electric Utility Industry

When projects are sold with fixed prices, it is utterly important to quickly and accurately estimate the effort required to enable an optimal bidding. This paper describes a case study performed at a leading IT provider within the electric utility industry, with the purpose of improving the ability to early produce effort estimates of projects where standard functionality is delivered. The absence of reliable historic data made expert judgment the only appropriate foundation for estimates, with difficulties of quickly develop estimates and reuse or modify estimates already made. To overcome these troubling issues, the expert estimates were incorporated into a model where they and the factors influencing them are traceable and readily expressed. The model is based on decomposition of projects and bottom-up estimation of them, where impact of relevant variables is estimated by assessing discrete scenarios. It provides quick and straightforward means of developing estimates of the decomposed elements and whole projects in various circumstances, where not only expected effort is considered, but the uncertainty of the individual estimates is visualized as well. Which together with the traceability enables the estimates produced by the model to be assessed, analyzed and refined as more details of the project is known.