The design and construction of cleanrooms and contamination controlled facilities often represent a complex undertaking for a project team. In addition, many times these projects must be delivered on an accelerated schedule in order to meet the client’s requirements that are the result of marketplace pressures. Often with traditional project delivery methods, one of the cardinal project elements (cost, time, and quality; generally cost in cleanrooms and contamination–controlled facilities) must be compromised in order to meet the project requirements.

There does exist another option. The lean project delivery system as developed by the Lean Construction Institute (LCI) offers a project delivery system that has proven capable of delivering projects (particularly complex ones) with reduced costs, accelerated schedules, and improved quality. In addition, the lean project delivery system has improved the safety record of projects that it has been employed on.

Lean construction began in Europe in the early 1990’s as an offshoot of the lean manufacturing movement that was started by Toyota and advanced in the US by the work of Jim Womack and the Lean Enterprise Institute. For those not familiar with the principles of lean manufacturing, the focus is on the reduction of waste (or in the jargon of Lean Manufacturing, “muda,” loosely translated from the Japanese as “waste”) and in the creation of customer based value. Lean Manufacturing has now become one of the most significant forces for transforming the manufacturing world.

Many in the construction industry have rejected the ideas from lean manufacturing, but upon closer inspection it can be seen that the waste in both manufacturing and construction arise from the same activity-centered thinking. Taiichi Ohno, the founder of the lean manufacturing movement at Toyota, stated, “Keep intense pressure for production on every activity because reducing the cost and duration of each step is the key to improvement.” The construction process under lean is different from typical practice because it:

*Sets clear objectives for the delivery process*  Activities*  Responsible PersonsWeeks 1, 2, 5, & 6 by day check-off listConstraint analysis comprising:

* Aims at maximizing performance for the customer at the project level

* Designs concurrently product and process

* Applies production control throughout the life of the project

The theory of lean construction is that projects are temporary production systems linked to multiple, enduring production systems, from which the project is supplied materials, information, and resources. Every production system integrates designing and making a product. Project management is understood in terms of design, operating, and improving production systems.

Today, most projects are still managed by processes that came into accepted practice in 1960. These processes have only been updated, revised and restated. It works this way:

The current forms of project delivery in construction aim to optimize the project activity by activity and assumes that customer value has been identified in design. Production (activities) is managed by first breaking the project into pieces, then putting the pieces into logical sequences, estimating the time, resources, and cost required to complete each activity. Each activity is further broken down and either contracted out or assigned to a task leader (job captain, foreman ,etc.). Control consists of monitoring each activity and comparing it against its schedule and budget value (projection). The projections of the individual activities are summarized into project level reports. If activities or sequences of activities in the critical path fall behind, efforts are made to reduce the cost and duration of the activity or sequence. If the remedial steps do not solve the problem, it is often necessary to adjust the work sequence, trading cost for time and in some instances sacrificing quality. This focus on activities conceals waste and ignores flow and value considerations.

In lean construction, the reliable release of work between specialists in design, supply, and assembly (execution) assure that value is delivered to the customer and waste is reduced. Lean construction challenges the belief that there always must be a trade off between time, cost, and quality.

Project activities are interdependent. They share resources and the sequence and timing of tasks within one activity constrain downstream activities. Current project management practice cannot provide for this interdependence. As a consequence, waste abounds and value is lost under pressure to optimize cost and meet schedule deadlines.

In lean construction, the facility and its delivery process are designed together to better support the customer’s requirements. Work is structured throughout the process to maximize value and reduce waste at the project delivery level. Efforts to manage and improve performance are aimed at improving total project performance rather than just at reducing cost or increasing the speed of any activity. Control is redefined from “monitoring results” to “making things happen.” The performance of planning and control systems are measured and improved.

The Lean Project Delivery System structures the work-flow into logical, overlapping, interdependent phases. It differs from traditional delivery systems in the definitions of the phases, the relationship between them, and the participants in each phase. Figure 1 illustrates the lean project delivery system. The overlapping triangles represent the phases and the boxes represent the principle elements of each phase. Note that:

*  The project is structured and managed as a value generating process

*  Downstream stakeholders are involved in front-end planning and design through cross-functional teams

*  Project control has the job of execution as opposed to reliance on after-the-fact variance detection and reporting

*  Optimization efforts are focused on making work flow reliable as opposed to improving productivity

*  Pull techniques are used to govern the flow of materials and information through networks of cooperating specialists

*  Capacity and inventory buffers are used to absorb variability

*  Feedback loops are incorporated at every level; dedicated to rapid adjustment; i.e. learning

Project Definition

The project definition phase includes needs and value analysis, design criteria, and design concepts. In the definition phase, all project stakeholders are participants in the decision making process. Conceptual designs will be generated and assessed based on needs determination. They will be cost and schedule modeled. As alignment between customer needs and stakeholder demands occur, the design criteria for the product(s) and process(es) will progress to design concepts (the start of lean design).

Lean Design

When values and criteria are aligned, the process enters the lean design phase. Lean design progresses from design concepts (more than one concept may be brought forward from the definition phase) to product and process design. The first action of process design will be to design the design process. The design team is responsible for this activity and the product of this activity will be a design structure matrix properly sequencing tasks in order to reduce needless iterations. Design decisions will be deferred until the last possible moment in order to allow more time for developing and exploring alternatives. Specialty contractors (if appropriate) will participate in the design process either as designers or in assisting with the selection of equipment and components. Operations design as a part of process design will be initiated and incorporated into the overall project concept. When the process and product design have been developed from a single design concept consistent with the design criteria (based on customer needs and stakeholder demands), lean design transitions to lean supply.

Lean Supply

Lean supply consists of the detailed engineering of the product design produced in lean design, then fabrication or procurement of components and materials and the management of the deliveries and inventories. All decisions made in lean supply are focused on maximizing customer value. Lean manufacturing techniques will be applied to the fabrication shops and required of vendors providing components and materials. Supply chains will be mapped to provided a clear understanding of the dependencies and relationships. Process design will seek to minimize inventories, right-sizing them to the flow variability that cannot be eliminated. When deliveries begin, lean supply transitions to lean assembly (execution). Deliveries may be fast-tracked so that assembly of one component can begin while detailed engineering of subsequent (successor) activities is still underway.

Lean Assembly (execution)

Lean assembly begins with the delivery of materials and relevant information for their installation. The assembly process will be managed using the “Last Planner” incorporating look ahead planning, pull scheduling, constraint analysis, and plan reliability tracking. In lean assembly, the first line supervisor’s role will change from giving orders to coaching and managing improvement. One focus of the process design of the assembly phase will be “one touch” material handling (waste reduction). Lean assembly is finished when the client has taken beneficial occupancy and commissioning has been completed.

In the lean project delivery system, production control governs the execution of plans and extends throughout the project. “Control” first means causing a desired future state rather than identifying variances between plan and actual. “Last Planner” is the name of the Lean Construction Institute’s system of production control.

Work structuring is the development of operation and process design in alignment with product design, the structure of supply chains, allocation of resources, and the design of assembly efforts. The purpose of work structuring is to make work more reliable and quick while delivering value to the customer.

Three of the principle “tools” used in implementing the lean project delivery system are: the “Last Planner” system of production control; work structuring; and reduction of negative iteration in design.

The Last Planner system of production control is principally the practice of eliciting promises and declarations of completion of those activities that release work to others. This allows the project to stay in the desired sequence and advance as quickly as possible. The principles of Last Planner involve inserting activities into a six week look ahead schedule, screening them for constraints and advancing them only if all constraints can be removed. Assignments must be made based on quality. The percentage of assignment completed is tracked and the reason(s) for failure reviewed and analyzed to prevent being repeated (learning). Detailed work plans are developed (one week look ahead schedules) and a backlog of ready work is maintained to provide a buffer for system variability.

A typical schedule would be a 6 week look-ahead schedule consisting of:

*  

*  

* Contract/C.O.s

* Safety

*  Space Planning

*  Budget

* Engineering

* Submittals

*  RFIs

*  Materials

*  Labor

*  Equipment

*  Prerequisite work

* Space

* Explanation of constraints*  Action required by*  Workable backlog The waste of overproduction (inventory, work-in-progress) is eliminated• J. Womack, D. Jones. “Lean Thinking,” 1996, (Simon & Schuster, ISBN 0-684-81035-2, 1996).Note: This article references various work from the Lean Construction Institute, www.leanconstruction.org . Materials in quotes are direct from LCI sources. Any of the readings (papers, case studies, etc.) are available for public review from the Lean Construction Institute library www.leanconstruction.org .

Work Structuring is defined as “process design” and is based on “pull techniques.” The final products of work structuring are schedules. “Pull” is based on working backwards from the target completion date. By working backwards from the completion date:

*  Work is done that only releases work to someone else

*

*  Working backwards eliminates work that has typically been done but that does not add value

 In design, it has been found (through various studies) that up to 50% of design time can be spent on needless (negative) iterations. This has occurred for many reasons that have evolved as design has been separated from the other core project processes (process design, fabrication, assembly, etc.).

Negative iteration can be reduced by the following techniques:

*  Use of a design structure matrix as part of the management of the design process

*  Team problem-solving

*  Cross-functional teams

*  Shared range of acceptable solutions

*  Sharing of incomplete information

*  Reduced batch sizes

*  Team pull scheduling

*  Concurrent design

*  Deferred commitment

*  Set-based vs. point-based design

Conclusions

When the “Lean Project Delivery Process” is compared to “Traditional” delivery processes it becomes clear that there are significant differences as illustrated in Table 1.

Lean project delivery is clearly different but is it better? Current data indicates that Lean Project Delivery can:

*  Result in a 10% - 15% reduction in cost

*  Result in a 15% - 20% improvement in project schedule

*  Result in up to 100% improvement in quality as measured by “punchlists” and “call-backs”

*  Result in a significant improvement in risk management

*  Lower overall accident rate

*  Lower overall lost time incident occurrence rate

For complex and “fast-tracked,” schedule-driven (time to market) projects (such as many cleanrooms and contamination controlled facilities), the results are even more significant.

The project delivery industry (design, construction, and suppliers) is beginning to embrace lean construction and it is becoming a significant force for change in the way we deliver projects. Many major companies (Intel, Ford, Lockheed-Martin, and others) are now using lean construction as a principle project delivery method.

Lean construction and the Lean Project Delivery System may not be the right delivery method for every project. However, for the great majority of projects that result from technologies that require cleanrooms and contamination controlled facilities, it can offer excellent opportunities to provide clients, high quality, high value projects, in as short a time period as is reasonable.

To quote the motto of Lean Project Delivery, “Give customers (both external and internal) what they want, deliver it instantly, with no waste”

Suggested Readings:

• M. Rother, J. Shook. “Learning to See,”(Lean Enterprise Institute, ISBN 0-9667843-0-8, 1999).

• M. Rother, R. Harris. “Creating Continuous Flow,” (Lean Enterprise Institute, ISBN 0-9667843-3-2, 2001).

Acknowledgment: The author would like to thank Greg Howell and the Lean Construction Institute for their support and making the reference materials of the Institute available for use.