Intrigued. As an architect and green building consultant who cares about the environment, I don’t like wasting things. Thus, I have become intrigued by a method of reducing manufacturing waste developed by Toyota and later coined “Lean” by a former Toyota engineer. A method aimed at reducing waste seemed to me, at least on the surface, to be well aligned with LEED. But when my obligatory Google search resulted in little that connected Lean and LEED in any meaningful way, I began to examine a process based on Lean principles to uncover what it might have to offer to a typical LEED project.
I have found much in Lean that could work for LEED. In particular, Lean emphasizes a process for value creation, something that I have looked for in LEED projects. I now intend to focus more on value creation in my work, and hope that owners and others in the architecture, engineering and construction (A/E/C) industry follow suit. Value creation appears to be well aligned with the goal of building in a sustainable manner.
Lean is a method for creating a desired result with the fewest processes, in the least amount of time and with the least amount of materials. Its principles quickly spread throughout the manufacturing industry, and Lean is beginning to make its way into the A/E/C industry. As defined by the National Institute of Standards and Technology’s Manufacturing Extension Partnership, a part of the U.S. Department of Commerce, Lean is “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.” According to Lean Thinking, the quintessential book by James Womack and Daniel Jones, the five principles in Lean are: value, value stream, flow, pull and perfection. Each of these principles has the potential to benefit LEED projects.
Value in Lean. In Lean, the goal is to create value, whether through a manufacturing process or a service. Value is what is important to the ultimate customer. The manufacturer or service provider must involve the ultimate customer in the value definition process. Once value is clearly defined, the process or service can proceed toward creating it.
Value in a Building Project. Based on the value principle in Lean, the owner of a building project should explore the project’s value early, and not just the value to the owner but also to the ultimate customer, including potential stakeholders. The owner may need the advice of the project team to understand available project options for creating value.
LEED Potential for Value. Some rating systems under LEED v2009 and LEED v4 set the stage for defining value by referring to the owner’s project requirements (OPR) document or by emphasizing an integrated design process. The integrated processes and OPR described in LEED can be used to define and document value early during the project’s conception which is consistent with Lean.
Value in the Current LEED Process. Currently, as a project team we often find ourselves at a LEED kickoff meeting with a project owner who has declared interest in LEED certification and is ready to go through the LEED checklist to see what points may have affordable first cost and could be pursued, with the implicit hope that this creates value. Typically, at this point the project team has no OPR or basis of design (BOD), but the project is at 50 percent or 100 percent schematic design or further since this is when most consultants are brought in.
Value in the Proposed LEED Process Based on Lean. A better process would start earlier, when the owner identifies a need for new or upgraded space, long before the general location and the specific site is chosen. The owner may involve ultimate customers of the building project in this early phase. These stakeholders might be future or representative members of groups directly affected by the building, such as occupants, real estate brokers, investors and members of the community. If LEED appears to be related to the value considered for the project, a consultant knowledgeable in LEED would ideally be involved early on as a contributing facilitator and technical resource. The owner should document the results of the value definition process in the OPR early in the conception of the project with assistance from others as needed.
Value Stream in Lean. In Lean, as defined for manufacturers, the value stream consists of three processes that should be optimized toward creating the value:
- Problem solving
- Information management
The entire value stream should be differentiated into steps that are part of these three processes, while looking for:
- “Value-creating” steps that clearly create value
- “Unavoidable” steps that create no value but nevertheless must be done
- “Avoidable” steps that have no value
This investigation of the three processes and their steps should reach beyond the business unit to raw material and the consumer. The goal is to create a broader enterprise, a voluntary alliance of all stakeholders, focused on value creation throughout the life of the product.
Value Stream in a Building Project. For building projects, the project team’s corresponding value stream would thus consist of:
LEED Potential for Value Stream. LEED is commonly used as a tool supporting the process of design, documentation and construction. Even though LEED is not designed as a decision-making tool, LEED assists the project team in making decisions so that the project will be rated favorably under LEED.
LEED deals with all three processes of design, documentation and construction with the exception of the rating system for building operations (Existing Buildings: Operations and Maintenance), which however uses similar processes for planning, documentation and implementation.
All LEED projects could benefit from a closer look at how value stream optimization could support these processes.
Value Stream in the Current LEED Process. Exactly how the process of LEED design, documentation and construction is achieved is currently largely up to each individual project team member, perhaps under the guidance of a LEED specialist.
Most projects end up achieving a LEED certification level in a process that seems somewhat arbitrary compared to Lean.
Value Stream in the Proposed LEED Process Based on Lean. To create maximum value to the project, the process would clearly focus on steps that create value throughout design, documentation and construction.
Design and construction: The entire project team would create a BOD that, among other descriptions, provides the identification of LEED design and construction items. This BOD should provide the following sorting:
- Value-creating LEED steps clearly aligned with the OPR. These steps should be given the maximum attention.
- Unavoidable LEED steps that do not support any OPR priority other than simply obtaining a LEED certification. These steps should be minimized in their time and cost requirements for the project.
- Avoidable LEED steps that are not pursued as they have no value for the project.
Documentation: Similarly, the LEED documentation effort would identify:
- LEED documentation that creates value for the project beyond the LEED certification submittal, because it:
- leads directly to design and construction that supports value; or
- can be shared with stakeholders and supports their value priorities
- Unavoidable LEED documentation that is simply required to obtain a LEED certification, to be handled in the most efficient way.
- Avoidable LEED documentation, which should be prevented, such as extra, repeated and reworked documentation due to misunderstood value, unclear instructions, dropped points, extra points, change in project direction, pursuit of dead ends, etc.
Flow in Lean. In Lean, flow is a concept that is the opposite of batch thinking. Many conventional processes handle items in batches, waiting for a sufficient number of items to accumulate before they are forwarded, in a batch, to the next process. With flow, instead, some tasks are bundled to be performed simultaneously or in concert by a small cross-functional product team working on the same larger item. Picture a small team working on various parts of a car at the same time, before it goes down the line to another small team. The goal of bundling tasks is to:
- Reduce wait time for an item
- Reduce the repeated handling of the same item
Flow in a Building Project: The concept of flow in Lean is that tasks are handled in small cross-functional teams. In the case of design and construction, these teams may include owner and occupant representatives, designers, construction professionals, installers and suppliers who will make joint decisions that move the project toward its intended value. While this appears complex, the efficiencies come into play when a decision is made that satisfies the most team members and later revisiting becomes unnecessary.
In connection with Lean, the term “set-based design” has emerged, with a “set” understood to be a group of elements creating a solution. The project team will work with sets as follows, in sequence:
- In the beginning, empty sets consisting of broad design parameters are defined. These are similar to a performance specification and allow complex solution alternatives for each set.
- A replacement set is created for each empty set, consisting of all potential solution sets that satisfy the requirements of the empty set. Multiple potential solution sets, as well as any subset alternatives, are then explored concurrently by small cross-functional teams. These teams define tradeoffs and gradually narrow each replacement set while doing minimum work on the actual design of potential solution sets. They make decisions as late as they can with as much information as possible, leading to “just in time” decisions. As the replacement set narrows, the level of detail (or design fidelity) increases. The process of researching potential solutions in parallel allows the team to benefit from overlapping findings and arrive at a hybrid solution set.
- The solution set for each empty set is defined and revealed. The solution set needs to be sufficiently clear so that it can be refined further without any need to question itself.
Conventional point-based design is the opposite of set-based design. Traditionally, the problem point is quickly defined: The project team moves to define a design point, and then moves from this point to refine the design to the next point. Critical decisions are made early before all tradeoffs are explored and known, often based on little more than an educated guess. Batch-thinking is evident by moving entire designs through project phases without regard to the true development of each portion of the design. This point-based process leads to changes, inefficiencies and design compromises as earlier decisions are revisited when more information becomes known. Thus, point-based design leads to waste in the process and a less-than-optimal solution for the project in the end.
LEED Potential for Flow. LEED BD+C and ID+C v4 approach the ideas of set-based design in their versions of the credit “Integrative Process,” and LEED for Healthcare v4 does the same in the prerequisite “Integrated Project Planning and Design.”
In the BD+C v4 credit or the Healthcare v4 prerequisite the project team is to conduct an analysis of two empty sets, one for “energy-related systems” and a second for “water-related systems,” for one potential point. Each empty set has a number of empty subsets that rely heavily on the OPR and BOD documents. In a set-based design process, the LEED project team would work with replacement sets to arrive at two solution sets, one for energy and one for water-related systems.
In the ID+C v4 rating systems, this credit requires exploration of what appears to be two empty sets—one for site selection and a second for energy-related systems, with each set offering a number of subsets—for one potential point. The credit also offers a second point for exploration of a third empty set for water-related systems, also with a small number of subsets.
Read more about flow, pull and perfection in the article’s conclusion in the October issue of EDC.