WORKFLOW OPTIMIZATION WITH CONSTRUCTION SCHEDULING UNDER A LEAN PERSPECTIVE

Construction scheduling produces the most important construction documents as they disclose the total project duration, project stages and times of work packages, activity costs per time period, logical sequence of activities and corresponding consequences for quality and safety. The production model displayed by the schedule should address Lean principles of production, mainly the reduction of waste created by idle time of crews due to a non-optimized workflow and takt-time planning. In a Lean Construction perspective, the project schedule should address the workflow of activities and of construction crews through the workspaces of the building. Location-Based Management System (LBMS) is a recent and innovative method that aims at planning and managing construction projects in a process-oriented way. This approach is based upon the Location Breakdown Structure (LBS), a hierarchical categorization of the workspaces where construction activities are performed by trades. As different trades need different types of workspaces, the LBS should be trade and time dependent. In an on-going research an improved scheduling method for construction operations has been developed, based on a CPM - Precedence Network plotted on a Resource–Space chart. Space Units of the project work are identified by a Location Breakdown Structure (LBS), and project activities are identified by two dimensions coordinate system based on Resources (i.e. construction crews) and working spaces (e.g. floors of a multi-storey building). Therefore the network model can be structured understanding resource and space constraints. Space Units can be modified in different stages of the execution according to trade – specific requirements, therefore creating a time-dependent LBS, and resource-based activity plotting can enhance workflow modeling through locations. Takt time of workflow in each space unit can be easily detected and optimized through balancing the duration of the sequenced activities of the space unit. The aim of the proposed approach is to increase the quality of the produced schedule by addressing Lean principles concerning work-flow optimization and takt-time detection and planning. The scheduling approach has been tested on a sample project.