Laptali, E (1996) Application of optimisation techniques to planning and estimating decisions in the building process. PhD thesis, University of Glamorgan, UK.
Abstract
An integrated computer model for time and cost optimisation has been developed for multi-storey reinforced concrete office buildings. The development of the model has been based on interviews completed with Planners, Estimators and Researchers within 2 of the top 20 (in terms of turnover) UK main contractors, and on published literature, bar charts and bills of quantities of concrete framed commercial buildings. The duration and cost of construction of a typical multistorey reinforced concrete office building is calculated through the first part of the integrated model, i.e. the simulation model. The model provides a set of choices for the selection of materials and plant and possible methods of work. It also requires the user to input the quantities of work, gang sizes and the quantity of plant required, lag values between activities, output rates, unit costs of plant, labour costs and indirect costs. A linked bar chart is drawn automatically by using the data available from the simulation model. The second part of the model, (optimisation) uses the data provided by the simulation part and provides sets of solutions of time vs. cost from which the minimum project cost corresponding to the optimum project duration is calculated under the given schedule restrictions. Linear programming is used for the optimisation problem. The objective function is set to be the minimisation of the project cost which is the total of the direct costs of all the activities creating the project and the indirect costs of the project. The constraints are formulated from the precedence relationship, lag values, and normal and crash values of time and cost for the activities supplied by the simulation model. The simulation part has been validated by comparing and contrasting the results with those methods and practices adopted by commercial planners and estimators. The validation of the optimisation part has been undertaken by plotting time-direct cost curves from the results and checking the convexity of the curves. Additionally, the validation procedures included taking account of the opinions of practitioners in the industry on the practical and commercial viability of the model.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Uncontrolled Keywords: | concrete; direct costs; duration; estimator; indirect cost; interview; linear programming; materials; multi-storey; optimisation; programming; reinforced concrete; simulation; UK |
| Index terms: | building process, optimization technique, direct cost, interview, bills of quantities, commercial building, turnover, estimator, validation, unit cost, main contractor, cost optimization, minimization, integrated model, duration, reinforced concrete, precedence relationship, office building, linear programming, practitioner, labour cost, indirect cost, planner, project cost, programming, estimating |
| Subjects: | building construction, algorithms, construction type, programming, cost management, profession, project controls, practitioner, economics, data collection methods, operations research, professional development, analytical methods, building materials, financial and cost management, business management |
| Topics: | Construction Materials, Digital Applications, Roles and Professions, Research Practice, Information Management, Construction Technology, Procurement, Cost Management, Business Strategy, Time Control, Site Management |
| Descriptive scope: | 4 PCEA |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here