||Generating a realistic plan at the beginning of a project and maintaining itsreliability throughout the construction is not an easy task. A case study of a 120million pounds Private Finance Initiative (PFI) project in UK indicatesunreliability of the construction plan (Percent Plan Completion (PPC) less 40%)which was caused by the lack of co-ordination among work-face personnel, projectplanners, and supportive organisations (i.e. designers, suppliers, andsubcontractors). In this case, wastes regarding waiting for design information anddiscrepancy supply of resources are considerable. These wastes, apparently, lowerproductivity and affect time and cost of the project.Aiming to treat the above problems, this paper identifies an improvement strategythrough a synergy of: 1) an innovative construction project management paradigmnamely lean construction; and 2) the advanced information technologies namelyweb-based information management, and 4D visualisation. This has resulted in adeveloping prototype called "LEWIS - Lean Enterprise Web-based InformationSystem for Construction". A unique structure of the system is an integration ofproduct model, process model, and information management functions. Not beingmerely the information warehouse, the system allows planners to perform lookaheadanalysis, rehearse the plan, and visualise execution constraints in the 4Denvironment. It is envisaged that this system will facilitate co-ordination amongproject participants, increase reliability of construction plan, and improve on-siteproductivity. The focus of this paper is on the overall system architecture,information repository, and web-based interfaces while the 4D constraint-basedanalysis and visualisation is detailed in a companion paper.