The use of Last Planner System in highly specialised construction projects

Developed by Zsofia Dora Helmeczi

Who knows it better how and when to do it than the specialists themselves? During the construction of highly specialized buildings like world-class research facilities or hospitals, the Last Planner System can be a useful tool to project managers for achieving the most optimized time- and activity schedules, even with several different participants and construction companies on site. The end users of these buildings are very dedicated and passionate about their professions. In order to build facilities technologically so advanced and valuable to them, the involvement of expert knowledge early on the construction process is a necessity.

The Last Planner System was created by Glenn Ballard and Greg Howell in the 1980s with the purpose to improve the reliability and predictability of the construction production. LPS is managed on four different scheduling levels that offers a collaborative way of project management which enables issues to be identified and resolved even before they become problems on the construction site and helps to reach project completion on time.

The key word in Last Planner System is collaboration. By this we mean an open and transparent discussion between the foremen and site-management from different disciplines who will schedule the processes together. Beside the important advantages, this article will also include the concerns and questions when managers implement the Last Planner System and how to avoid or mitigate these risks during an ongoing construction project. Finally, the article will introduce an example from real life - the Copenhagen Plant Science Center - where the Last Planner System could have been an efficient tool in the hands of the project management.

Overview

Video 1. The Last Planner System by Lean Construction Institue

The Last Planner System was created by Glenn Ballard and Greg Howell in the 1980s with the purpose to improve the reliability and predictability of the construction production. The LPS is a collaborative process which principal method is to use the knowledge and skills of the experts and foremen who will execute the construction to plan how they want to do it. It creates better predictability through reliable schedules, better economy and budget planning, less errors with higher security and increased work satisfaction with optimized communication. It also has some risks during implementation, as is the case with any other method, and the article will focus on these in a paragraph.

Four Different Levels of Planning

The Last Planner System breaks down the planning and scheduling of a construction project into four levels, see in Fig.X. Each planning phase and discussion is kept between the foremen of each trade represented on the construction site. Unlike traditional planning where the project managers are active part of the scheduling, in the LPS they have to participate in the meetings without interfering in the discussion of the foremen. Their job in the planning phase is to facilitate these meetings, document and later monitor whether the actual construction is according to plans, and help the communication between parties. The focus of project management shifts from initial planning to control and monitor the construction in the Last Planning System, and take corrective actions when “the ship appears to be off course.”

A detailed description of the four main phases are given in the following four sections.

Master Schedule

In the first phase, the initial deadlines are milestones are set for the construction project. These are strict deadlines that forms the base of the entire project and they must be met in order to finish the project on time.

Phase Schedule

Figure 1. Four Levels of Planning

After the project deadlines are discussed, the foremen will perform an initial planning mapping out of the whole construction project in time - this will be called the Phase Schedule. The main goal of this phase to determine how and in what order the activities should be carried out.

It is very important, that the foremen and experts get familiar with the drawings, requirements and specifications before they gather for the meeting of this phase. They need to prepare the list of activities and their early time estimations in order to be effective in the meeting. They have to write each of their activities on paper and place them in the timeline of the main deadlines. After all of them indicated their activities in the timeline, the process planning starts during they move the papers around and discuss with their fellow foremen the optimal positions of the activities. It is allowed for each profession to move their own paper - this way the owner of the activity will be included in the case of disagreement, and the activity will be only moved when the owner is convinced by the others. This also ensures that at the end a global agreement of the final processes and phase plan.

Look-Ahead Schedule

Often the Phase Plan is not detailed enough, and the participants get the opportunity to break it down into smaller details in the Look-ahead plan. The Look-ahead plan usually looks ahead for 6 weeks, and indicates whether there are any obstacles for each activities in the time period. It is updated weekly during the weekly planning meetings where the constraints like procurement of materials, prerequisite activities are reviewed. If any obstacle arises, the Look-ahead plan also includes the person who is responsible to solve the problem and when at latest it should be handled. The typical constraints are the following:

• Is the previous activities completed?
• Are the materials and equipment ordered and ready?
• Is the personnel qualified?
• Are the correct drawings and information available?
• Are the spaces optimal and safe enough for the activity to be carried out?
• What is the status of external circumstances, hereunder contracts, approvals, weather, etc.?

If all the above mentioned constraints are fulfilled, then the activity can be carried out.

Weekly Work Schedule

Each week, a short meeting is held by the foremen from each profession on site. During these meetings the aim is to specify when the upcoming activities will be carried out. Worth mentioning that only activities without constraints are part of the weekly work plan. Thus the meeting starts with the revision of the previous week, were the planned activities carried out or not? The efficiency of the previous planning can be measured by the ratio of the total number of finished activities in relation to the total amount of planned activities. This performance measurement system is called Percent Plan Complete (PPC).

$PPC=\frac {total\ amount\ of\ finished\ activities} {total\ amount\ of\ planned\ activities}$

The PPC indicator does not tell us whether the time schedule is being kept or not, but it shows how well the social planning and collaboration works between parties.

General Advantages of LPS

Better Workflow

In short, the main advantages of using the Last Planner System is less waste, improved cost management and greater job satisfaction. A much better workflow can be achieved on the construction site by focusing on the obstacles lying ahead in the schedule and remove them before the workflow reaches that point in time. The subcontractors can work without interruption and ideally won’t stop to wait for materials to arrive or a prerequisite activity to finish. This also means less waste of both time and resources among other characteristics, which makes the Last Planner System a usable “lean” tool in LEAN construction. All this means that the project can be completed faster than using the traditional project management methods used in building constructions, and faster completion means the subcontractors can move on earlier to their next projects and thus increase their earnings. Another positive result of LPS is that careful planning results fewer failures during construction and after handover. Less correction will be needed and it results in saving resources like time and money.

Figure 2. Phase Schedule

Safer Construction

Looking at safety during construction, studies shows that approximately 35% fewer accidents happen when using the Last Planner System. The increased collaboration in planning and execution of the tasks in a construction project means that several causes of accidents are identified and addressed even before the accident happens.

Increased Job Satisfaction

The increased job satisfaction among all participants is a direct result of that the subcontractors have more influence on their own work and they experience fewer and smaller obstacles in their daily work. Last Planner System adds a production control element to the traditional project management system. It can be understood as a mechanism for transforming what should be done into what can be done, thus forming an inventory of ready work from which the Weekly Work Plans can be formed. The assignments on these Weekly Plans show commitments by the foremen to what they actually will do in the next weeks. This feeling of a commitments made and accepted by their peers puts a social pressure on the teams to deliver on time and cooperate with the other subcontractors. Also, the process or project management team members can feel more satisfied and balanced because they can achieve a better production flow and avoid the constant need of having to “put out fires” and take care of minor problems. The subcontractors have a cooperative partnership among them because of the weekly meetings, they can coordinate and find solutions for the minor obstacles among themselves.

General Risks of LPS

How to Get Committed and Involved

The most important risk is how to make the subcontractors commit to the Last Planner System, especially if they haven’t used it before and don’t know the advantages of it. Rolf Simonsen from VærdiByg also emphasized the following key momentum in the system:

"It is important that the project management provides room for the subcontractors’ knowledge about the process to appear."

The management should not dominate and control the weekly planning meetings, they should just facilitate it and help if it needed. The subcontractors know when and how they can do their tasks, it is their opportunity to discuss and negotiate with their fellow partners in the project. If they feel that the meeting is all about the project manager’s opinion, they would bail and do not want to participate anymore. Similarly, if one of the subcontractors is dominant and too controlling over the others, it won’t provide optimal working conditions for the others – thus the overall project will face difficulties. It is important that all participants should be really involved in the planning.

Precise Time Estimates

Another risk is that people can overestimate the time needed for each task, add one or two extra days just to be on the safe side, and thus empty buffer times can occur in the schedule. While it can be good that there are buffers between the big milestones in a project, on the level of the Weekly Plans it is not 100% necessary. It is better to plan accurately and then put some larger buffers along the way. For this it is important that each participant should plan their own work and tasks before coordinating with the others. It is usually the case that the management puts a little pressure on the participants to meet the deadlines, but in the Last Planner System an honest answer to determine how long a task will take is always better than if someone accepts and agreement that they do not feel they can hold.

Knowledge of LPS as Prerequisite?

As Last Planner System is not commonly used in construction projects, subcontractors are not usually selected based on their understanding or willingness to participate in it. They are selected on traditional criteria such as financial soundness and bid price. They meet the system and the expectations about their responsibilities after they come to the site. After getting to know their new roles in the planning process, some can be more capable and enthusiastic about participating than others. After all, the social pressure they feel after bonding with other subcontractors on the weekly planning sessions will help to make them feel accountable for their commitments. Nonetheless one preferable solution can be to incorporate the participation in LPS into the selection criteria and written subcontracts and to organize trainings about the system if needed.

Implementation

While the Last Planner System is mainly used in the building phase of a project, it would result in a more collaborative cooperation if the client, the architects and engineers are involved in the production control process, preferably from the beginning of the design phase. It could eliminate the problems that comes from the separation of design and construction, e.g. the designer architect or engineer has a different idea about the implementation or realization of a building design feature. If we ask the specialist early on that how can something be built, we can avoid big obstacles in the construction phase.

Failures in a project can occur even using the Last Planner System. Nonetheless, continuously keeping track of problems, identifying and addressing issues is important immediately after they occur. It is required to analyze the reasons behind the problems as soon as possible to deal with the successfully. A well prepared weekly session after a problem occur can find a flexible solution without big sacrifices and loss in resources.

Why is it good for highly specialised construction projects?

An example - the Copenhagen Plant Science Centre

As an example, the Copenhagen Plant Science Centre construction project can be mentioned. The University of Copenhagen announced an architectural competition for its new research institute, and the winner was Lundgaard and Tranberg Architects in consortium with Jacobs Engineering Group, Kristine Jensen Architects and Emendo. Their proposition was a 6800 m2 cellular-style building complex with a modular system for 200 million kr. The building will house world-class research laboratories now and will be flexible for technology changes to stay top-notch more than 10 years later as well. This project requires a deep technical knowledge both from the designers and the construction teams to achieve the best possible solution to serve as a valuable research facility for the scientists and students. A well-managed platform is needed to help the collaboration of the architects, engineers, commune officials, financial management and end users. Also, big projects like this tend to have changes in design and requirements along the way. it is then important to minimize the cost and time impact of change management during the design, construction and facility management. To solve these two main challenges, LEAN construction may the best method. However, the Last Planner System is an ideal tool to manage construction projects with highly technical requirements, and it is easily utilized in LEAN Construction projects. Beside LPS, there a number of other tools that can come handy in project like these, for example Location Based Planning, BIM, end-user involvement, etc., but these tools are not in the focus of this article.

Conclusion

The Last Planner System allows us to involve the expert people in the scheduling, because they are the ones who know how to build something in a safe and precise manner with an efficient use of resources. The collaboration of the subcontractors from different fields provide a feel of a common project, the project would become transparent both for the parties in the construction and the client – everybody will know what the other is doing and when.

Additionally, when building laboratories extra safety measures and controls should be used. Gases and other dangerous materials should be installed extra carefully. For this specialist subcontractors are needed and the Last Planner System allows these specialists to decide and negotiate about the optimal time and ways for the installations in the work flow. It would result in a safer work environment with less accidents.

Annotated Bibliography

From the list of referenced materials - in the author's opinion - the following 3 are the best sources to get an initial understanding of the use of the Last Planner System. Two of them can be easily accessed through their online versions:

• Herman Glenn Ballard (2000) The Last Planner System of Production Control (http://leanconstruction.dk/media/9030/Guide%20-%20Last%20Planner%20System%20-%20dec%202009.pdf)

A university doctoral thesis that focuses on the application and result of Last Planner System on production management with the help of numerous case studies.

• VÆRDISKABENDE BYGGEPROCES (2013) "Involvement of Subcontractors (Inddragelse af Under Entreprenører)" ( http://www.vaerdibyg.dk/index.php?option=com_docman&task=cat_view&gid=69&Itemid=301)

Value Creating Construction Process is a co-operation between seven of the Danish construction sector's leading organisations. This co-operation offers several handbooks in different topics for people working in the construction business .

The third article is available on request:

• Karolyi, A., Asrihi, H., Saliba, R. H., Lindhardt Iversen, R., Samir Faak, S., Bartholdy Glindorf, V., Helmeczi, Zs. D., “Group Report for Planning and Management in Construction”

This academic report was prepared as part of the course called Planning and Management in Construction at Denmark's Tekniske Universitet (DTU). The report focuses on the possible management tools from various lectures connected to a case, with the focus on Lean Construction. Due the confidential character of the opinions expressed by the interviewees and according to their desires, the article cannot be distributed for publication.