Estimating, planning and control systems based on production data in the construction industry.

The processes of estimating, planning and control within the building industry are seldom fully integrated. This study considers the integration of the processes based on production data collected from several projects. The aim of the research is to investigate the feasibility of the integrated approach as a means of improving the estimating, planning and control processes within the construction industry.Selected cost significant work sections are considered in the study and production data are formulated based on feedback information from several first sample projects. Comparisons are made between average production data and individual project data.A structured systems analysis of the collaborating body identifies existing processes and production orientated information requirements. A model and working system prototype are developed which illustrate integration of the processes and generation of management information.Application of the model as a basis for estimating and planning at various levels of detail is demonstrated. Forecast-observation diagrams provide the necessary control mechanism for monitoring production outputs.Forecasts on a second independent sample of projects are assessed based on tolerances of performances from first sample projects. Accuracy of average forecasts from the model are compared with other data sources, these being estimators' data used in the preparation of the estimate, and bonus surveyors' targets used during the production process.The research concludes that the production data and model give a worthwhile improvement over existing methods in forecasting average productivity performances when methods of placing can be clearly identified and related to work packages. The production data and model are insufficiently accurate to give a worthwhile improvement when measured items cover work packages of varying degrees of complexity, and when proportioning methods are used to obtain production data for different categories of items which collectively represent work packages. Assessment of the model together with refinements are also discussed.