The goals of Lean Construction are to avoid waste, improve productivity and decrease variability. (Review Part 1 of this post, Scheduling with Lean Principles.)
The main tool to achieve this goal, the Last Planner SystemTM has been developed by the Lean Construction Institute and has become almost synonymous with Lean Construction in the US. The Last Planner System is based on techniques of late planning and reliable promising. Pre-planned master schedules are limited to milestones, and give constraints to phase schedules which are developed by the team, who will do the work. Phase scheduling is pull scheduling - the schedule is developed by working backward from a target completion date, which causes the tasks to be defined and sequenced so that their completion releases work. The best known part of Last Planner is weekly or daily planning, where commitments are tracked and measured by calculating the percentage of plan completed (PPC) for each week. For each failed weekly or daily assignment, a root cause analysis is done to prevent the problem from happening again. This social learning process improves the reliability of promises. Lean Construction tries to make all planning collaborative, and dismisses the traditional Command & Control planning approaches, where a centralized planning division creates plans and tries to make the field to follow them.
Location-based management systems try to achieve the same goals. Instead of focusing on the assignment level, the tools focus on planning continuous flow, and forecasting problems before they happen to enable timely reaction. The goal is to achieve an assembly line of continuous production on the construction site. Location-based management systems have a long history, and have been dismissed by Lean Construction communities as Command & Control tools. My PhD research shows that the Command & Control approach does not work, and the location-based management tools should be used in a collaborative way, incorporating the knowledge of the subcontractors into the planning process.
The Last Planner System lacks explicit tools for pre-planning, phase scheduling and look-ahead planning. Location-based management system has tools to pre-plan the assembly line of production, adjust it during phase scheduling, forecast future problems to help in the look-ahead process. However, it lacks the critically important tools of execution - transforming the plan into weekly or daily commitments and tracking those commitments. My PhD research suggests that the PPC is strongly correlated to plan reliability on master schedule and phase schedule levels. It seems that there is a big synergy between the two methods.
Location-based management gives a systematic process and tools for Last Planners to improve their PPC while maintaining the link to the master and phase schedules. During planning phase, continuous workflow can be planned to get a good understanding of required capacity. This can be implemented in a phase scheduling meeting using a collaborative process. An objective, mathematical procedure is used to forecast upcoming production problems based on progress so far, and the knowledge of available capacity in the upcoming weeks for each subcontractor. This forecast is adjusted by the use of control actions to prevent problems. (To see examples of this 4D coordination process, please review the archived webinar, Coordination Strategies for a Hard Bid.) The adjusted forecast can be used to validate the weekly plan assignments, together with other constraint information. Many things that earlier were learnt the hard way by first failing, and then learning from failures can be anticipated and prevented from happening.
Location-based management is a natural part of Lean Construction. Currently we are working to integrate the Last Planner System and the Location-Based Management System into a new, more powerful tool and process, to better achieve the goals of Lean Construction.
Learn more about the combination of Last Planner and Vico:
BIM 401: Model-Based Scheduling
4D Scheduling Strategies in a Hard Bid
We also offer a step-by-step guide to our 5D virtual construction workflow with video tutorials. These videos are just 2-5 minutes in length, but illustrate how to use a particular piece of functionality. You can access the video library index and view just what you need, or download the complete set of training videos. We have training levels for Estimators, Schedulers, Supers, and anyone who does CM Reporting.
The paper, The Combination of Last Planner and Location-Based Management System, co-authored with Glenn Ballard, explores the best practices for scheduling and controlling commercial construction projects, and will be presented this Summer at the 18th Annual Conference for the International Group for Lean Construction in Haifa.
