Integrating design and construction to improve constructability through an effective usage of IT

It is now widely recognised that bridging the gap between design and construction is essential for improving product quality, cost, lead time, and materials waste. The design of buildings has been separated from its production since at least the mid 19th century with professions growing up reinforcing this division. The result has not only led to the decay of integration but also to a growing misunderstanding of the role of each profession. This study proposed an information approach to improve the constructability of the design along with an object oriented analysis technique to model the design information. The model has been mapped into an object oriented development environment, leading to the development of a design tool for designers to use. The developed system aims to improve the constructability of the design without effecting the flexibility and creativity of the current design methods. Such an approach has enabled a closer link between design and construction through a better usage of IT, and the automation of 'Design to Construct' principles which do not diminish designers' creativity. Common design-related site problems have been established. Information related to these main problems have in turn been examined and traced all the way back to a top level process, i.e. the design stage. Information was analysed, using various techniques, with the aim of: a) identifying the degree of integration among the various design parties involved b) tracing back construction related problems to their relevant design processes, c) examining the impact of early design decisions on construction, and d) re-engineering the design function to incorporate a solution which acknowledges the identified site problems within the design function. This study attempted to break down the project's vast information into groups of related information which could easily be modelled, thus significantly narrowing down the amount of information involved and increasing the likelihood of producing a better information model leading to practical results. Such grouping was based on construction problem areas, as highlighted by previous research in this field, i.e. superstructure, substructure, finishing, etc. where each problem area could then be traced back to its design stage. Solutions produced for these groups could be incorporated into the design practice which could improve the constructability of the final product. Following this approach through a case study for one particular problem area, i.e. the superstructure of concrete frame office, a detail analysis was carried out. The main construction problems on site were identified, related sources of information were determined, and the relevant level of design, within which such problems could be eliminated or minimised were highlighted. A focused and well defined process analysis was then carried out to determine the relevant design processes along with their involved information and information flows. Shifting away from traditional structured methods of analysis, an object oriented technique was adopted to produce a data model for those design processes that have the greatest influence on construction problems. This technique proved to be very effective in producing a well structured data model with the consequence of being easily mapped into an object oriented development environment. An integrated object oriented system has been developed with the potential to improve the construction related problems. The system attempts to integrate essential information at an early stage in the design process such as; grid layout dimension, minimum floor to ceiling height, cladding type, maximum percentage clear glazed factor, beam and column construction types, and use it to produce information to generate the final building plan such as; beam, column and slab depths, window length and depth, revised grid layout dimension, revised floor to ceiling height, cladding arrangement. Both subjective and objective design information is translated into the final design outline. This system therefore, brings together the necessary information originating from various members within the design process and ensures this information is made available as and when required.