||Construction planning and control are identified among the top potential areasneeding improvements. A traditional technique known as the Critical Path Method(CPM) has been widely criticised in terms of its inability to cope with nonprecedenceconstraints, difficulty to evaluate and communicate interdependencies,and inadequacy for work-face productions. Attempting to treat these deficiencies,substantial research efforts have resulted in a wide range of advancementsincluding design of new planning and control methodologies and development ofsophisticated computerised applications. However, these efforts have not effectivelyovercome all of the above CPM drawbacks and, therefore, have not yet provided asolution to the industry.This paper identifies requirements for the next generation of the planning andcontrol as multi-constraints, visual, and lean-based system. In order to achieve thisgoal, important construction constraints and their characteristics are derived fromprevious literature. Various constraint detection and satisfaction techniques suchas knowledge-based system, advanced computational algorithm, and 4Dvisualisation are also investigated. As a part of the Lean Enterprise Web-basedInformation System (LEWIS) presented in the companion paper, a developingprototype called 4D constraint-based planning and control system is brieflydemonstrated. It is anticipated that successful implementation of this system willenable generation of reliable plans and constraint-free assignments, which will, inturn, reduce production risks and improve on-site productivity.