Estimating Task Duration

Introduction In project management, every project is composed of stages or steps that must be followed before the project can be completed or finished. Estimation can be defined as the process of scheduling tasks and the budgeting of resources for those tasks. The two most important components of these steps or stages are scheduling and budgeting. However, the difficult aspects of project management remain those centred on estimating task duration, including the execution and monitoring of tasks (Burns and Janamanchi, 2007). Project scheduling is using known project tasks (activities) and putting them into a timeline while project budgeting refers to the allocation of funds to the proposed tasks and deciding how, when and where such funds will be utilized. Assumptions are made in both cases before accuracy of estimate is established. In a nutshell, estimation of tasks that make up a project refers to scheduling and budgeting. Methods use for Estimating Task Duration The concept of estimating task duration cannot be thoroughly understood without, firstly, knowing what comprises the work breakdown structure. The use of planning and monitoring of projects and its importance and significance in project management is largely based on the degree of accuracy exhibited during estimation of task duration. In the past, numerous professionals have used different technique to explain this concept ranging from probabilistic to real time (Illumoka, 1987). Hill et.al (2000) itemized expert judgement, parametric models, function point analysis and newer approaches such as neural networks and case based reasoning. Wysocki (2009) suggested six methods, which include; Delphi technique, Expert advice, Historical data, Similarity to other activities or analogous estimation, Threepoint technique and Wide-band Delphi technique.

Expert advice This method of estimating task duration involves the use of expertise opinion from either an individual or group of individuals with vast

References: Burns, J.R and Janamanchi, B (2007) Improved methods for task estimation and project tracking, International Journal of Information Systems and Change Management, 2 (2), pp. 167-189 Goodman, P.A (1992) Application of cost-estimation techniques; industrial perspective, Information and Software Technology, 34 (6), pp. 379-382. Hill, J., Thomas, L.C and Allen, D.E (2002) Experts’ estimates of task durations in software development projects, International Journal of Project Management, 18 (1), pp. 13-21. Illumoka, A.A (1987) A tolerance analysis approach to network scheduling for engineering project management, International Journal of Production Research, 25 (4), pp. 531-547. Kerzner, H (1995) Project Management: a systems approach to planning scheduling and control, New York: van Nostrand Reinhold. Leach, L.P (1999) Critical chain project management improves project performance, Project Management Journal, 30 (2), pp. 37-51. Li, H and Love, P.E.D (1999) Combining rule-based experts systems and artificial neural networks for mark-up estimation, Construction Management and Economics, 17 (2), pp. 169-176. PMI, (2008) Project management body of knowledge (PMBOK Guide), Estimates activity durations: tools and techniques, 8th ed. Pennsylvania, PMI, pp. 149-151. Wallis, J., Burns, J and Capdevila, R (2009) Q methodology and a Delphi poll: a useful approach to researching a narrative approach to therapy, Journal of Qualitative Research in Psychology, 6 (3), pp. 173-190. Wysocki, R. K (2009) Effective project management: Traditional, Agile, Extreme. 5 th ed. Indianapolis: Wiley Publishing.