Part 1 in the September issue covered an introduction to Lean, the principles value and value stream, and the initial discussion of the flow principle.
Flow in the Current LEED Process. A common way to sort out LEED-related items is to have the entire project team participate in a design charrette. While a charrette may be able to start with well-defined empty sets (defining broad parameters) and create replacement sets (each consisting of all potential solution sets to satisfy an empty set), most charrettes are characterized by fast design and quick intuitive decisions, reducing the possibility of alternate solutions. Furthermore, an early charrette may not be able to create enough truly cross-functional teams that could create valid replacement sets. After a LEED charrette or kickoff meeting, most project teams proceed with a point-based design, quickly moving from defining the problem point to defining a design point, and then to refining the design to the next point.
Flow in the LEED Process based on Lean. Instead, an approach based on flow in Lean could be of great benefit for creating value with a LEED project. It would use a consistent set-based design process using several cross-functional teams, empty sets and replacement sets, and arrive at well-thought-out solution sets. Often, the pursuit of LEED involves complex scenarios within and across LEED categories. Exploring these scenarios consistently, and parallel with a set-based design process, appears to be an intelligent way to arrive at optimum solution sets for how a LEED certification can create the desired value for the project.
Pull in Lean. In Lean, items are not overproduced to fill channels and then pushed onto the customer. Rather, they are produced in smaller, more accurate amounts which then need to quickly meet the demand. Thus, the product user will create a pull on the value stream. Benefits include simplified communications, reduced inventory, shorter lead times, reduced work in-progress, improved cash flow and increased customer satisfaction.
Pull in a Building Project. In order to not overproduce, project teams can define clear project schedules with a critical path and associated tasks. Work schedules are refined each week to match current project status and needs. Project teams focus on critical path items first and allow for enough time and research to achieve knowledgeable progress of the project and to avoid rework. This approach to a project schedule goes hand-in-hand with a set-based design process.
LEED Potential for Pull. Because LEED v4 places more emphasis on integrative planning and design, one can expect that this will result in more streamlined processes and documentation for future LEED projects.
|Lean was implemented in auto manufacturing to create a product with the most value. The same thing can be done for LEED projects.|
Also, LEED v4 encourages building life-cycle impact reduction through available points in the Material and Resources category. In the BD+C v4 rating systems, projects can gain three points through a whole-building life-cycle assessment, a further development of a LEED pilot credit in LEED v2009. Looking at the life cycle of the building includes considering the life cycle of materials obtained for the building, including their quantities. In the v2009 rating systems, for example, there were no consequences for over-ordering building materials or tearing out incorrectly installed materials if the surplus materials were then donated to an organization, even though those materials might ultimately end up in a landfill. If one looks closely at quantities of materials acquired for a building, concerns such as over-ordering, rework and waste of materials move more into focus.
Pull in the Current LEED Process. The processes for design, documentation and construction, including the efficiency of each of these tasks and the potential of overproduction, are largely up to the individual project team members.
Pull in the Proposed LEED Process based on Lean. Applying the pull principle to LEED, everything related to the pursued credits and prerequisites in design, documentation and construction should be carefully managed and executed so that accurate amounts of effort support the value.
Perfection in Lean. As the principles of value, value stream, flow and pull interact, and as processes become more transparent and contributors of value can be identified and recognized with positive feedback, perfection can be reached. An underlying theme of Lean is the emphasis on no waste. Waste includes time (waiting), materials (defects, overproduction, extra inventory) and processes (extra, repeated or inefficient activities, transportation, lack of people engagement). In a Lean process, everything contributes to value, and there is no waste.
Perfection in a Building Project. In a project, this perfection would be evident in a very efficient process where the design, documentation and construction tasks are clearly worked out before construction occurs and where no rework or superfluous work occurs. This process should result, overall, in money and time saved.
LEED Potential for Perfection. While not explicitly stated, LEED incorporates fundamental values of reducing the use of resources, enhancing the quality of life and regenerating natural ecosystems. These are values consistent with the idea of creating no waste. In Lean, waste is anything that does not create Value. Thus, the two systems appear to aim for the same basic goal of waste reduction. A perfect Lean process would enhance a LEED project in essential ways: no time wasted in the design; no time, paper or electronic data storage wasted on documentation; and no time, labor, materials, water, energy or aspects of the natural environment wasted during construction, operations and maintenance, later renovations and deconstruction.
Perfection in the Current LEED Process. Currently, most projects pursuing LEED do not achieve perfection, as they do not start with a good value definition, nor do they look closely at a value stream with value-creating steps—unavoidable steps and avoidable steps. They generally do not create optimum solutions through flow in a set-based design process, but rather involve quick intuitive decisions in a point-based process. They tend to lack pull and involve overproduction in design, documentation and construction due to changes and rework.
Perfection in the Proposed LEED Process based on Lean. Viewing LEED projects as a process based on the five principles of Lean would go a long way toward achieving significant value for LEED-certified projects. Once Lean is followed for design, documentation and construction of a project pursuing LEED, the following process should crystallize:
- Value: The ultimate stakeholders of the LEED project will be involved in defining value, which will be documented very early during the conception of the project, in the owner’s project requirements (OPR).
- Value Stream: The basis of design will identify value-creating LEED steps, unavoidable LEED steps and avoidable LEED steps, in sync with the value definition of the OPR.
- Flow: Empty LEED sets will be defined in small cross-functional teams and be filled with broad LEED replacement sets and their potential LEED solution sets and subsets, to result in LEED solution sets made up of successful elements. A critical path schedule, weekly reviews of the needed tasks to address current needs, and a focus on informed just-in-time decisions will make the LEED project progress smoothly without any design, documentation or construction based on guesses.
- Pull: Overproduction, extra inventory and rework will be avoided. All tasks for the LEED project’s design, documentation and construction will create value.
- Perfection: No effort is wasted, and the LEED project outcome will be optimized and consistent with value.
A Lean-based LEED process could be well-suited for creating value with an optimized solution, pursued throughout design, documentation and construction. LEED already has some basic principles in place to support such a process. Yet, for a LEED pursuit to create the desired value, some changes may be needed to the prevailing method of LEED implementation.
In Part 1, we looked at the definition of Lean: “A systematic approach to identifying and eliminating waste (non-value-added activities) through continuous improvement by flowing the product at the pull of the customer in pursuit of perfection.” When more thought is given to a LEED value-creating process, and if one broadens the view of LEED (thinking how it applies to various projects in the built environment each with its entire life cycle), a new Lean-based LEED process might evolve. Its own definition might be “A systematic approach to creating value in the entire life cycle of built-environment projects, including their planning, design, construction, operation, renovation and deconstruction, related documentation, and to identifying and eliminating waste (non-value-added activities) through continuous improvement by flowing all tasks at the pull of the ultimate stakeholders in pursuit of perfection.”