Bringing Lean Design into Practice

Managing the Design Phase

Research unanimously indicated that the way project front-end is managed will have important impacts on the outcome of construction projects both technically and economically [1]. In fact, during these stages, when the needs and expectations of the project customers are converted into a physical model, several decisions are made. These decisions may lead to their satisfaction or dissatisfaction. In addition, a large number of professionals are involved such as architects, project managers, discipline engineers, etc. Each category of professionals has a different background, and learning style, which makes the design process more complex. 

Several authors proposed the Lean Design as a solution to these managerial challenges [2, 3]. According to them, the application of lean principles to the design management should have a significant impact on the value of costumers and reduces waste. However, what does Lean Design mean? And how can we implement Lean Design methods/tools in the construction industry?

Unclear Terminology and Definition

After conducting a thorough analysis of the concept of “Lean Design,” in the literature, we found the research on this subject to be confusing in terms of definition and description. 

In fact, although publications generally adopt the terminology “Lean Design,” three other expressions are found in literature, “Lean Design Management,” “Lean Design Process,” and “Lean Design and Construction.” The term may change depending on the focus of the article, emphasizing the management aspects when using Lean Design Management, or focusing on the process aspects when using Lean Design Process. 

In addition, there is no noticeable clear definition of Lean Design. More specifically, four main perspectives for a Lean Design definition are used: 1) Work management and information flow, 2) process and product, 3) TFV (Transformation, Flow, and Value), 4) Design for X.   

1. Work management and Information Flow: From this perspective, the aim of Lean Design is to improve the processes and operational activities of the design phase as well as the information flow between the stakeholders [4].
2. Process and Product: The objective of Lean Design from this perspective is to improve the designed product and also the management of design processes in order to meet client value [5].
3. TFV (Transformation, Flow, and Value): As the production in the construction industry means making and designing, the authors with this perspective explain that Lean Design should take into account different aspects of production, namely transformation, flow, and value. Transformation refers to conversion from input to output, while flow is about reducing waste in the design process, and value is directly related to management and communication between clients and professionals [6].
4. Design For X: The aim of Lean Design here is to take into consideration during the design development the constraints of manufacturing processes for the proposed facility. Design For X refers to maintainability, constructability, etc. of the specific phase that should be improved during the design phase [7].

The Gap between Methods and Perspectives

 Another inconsistency about Lean Design is how it should be implemented. Most authors do not explain, from their Lean Design perspective how and why the methods/tools they proposed could be used to improve the design process and outcomes.  Most of the proposed methods/tools are not used in the construction sector. They are usually derived from other industries. 

Conclusion

Serious inconsistencies in Lean Design literature were identified in this study. The wide range of interpretations makes it difficult to establish the exact meaning of this term. Also, in some papers, the terminology is presented without further detailed explanation on how it could be implemented in real-life practice. A lack of know-how is considered as one barrier of Lean implementation [8]. However, it would probably be inappropriate to talk about methods/tools without offering a definition of Lean Design. For this reason and for those cited above, we propose the following Lean Design definition that unifies all four perspectives: “Lean Design is an approach based on the production theory [9]. It aims to improve information flow and both product and process designs to align them with the project constraints, while considering people, technology and constructability of the product.”

Thus, the first contribution of this research is to provide a better understanding of the current Lean Design literature in the construction sector. Secondly, it is to present the different Lean Design definition perspectives, and the inconsistencies between these perspectives and the methods/tools proposed, which can affect implementation. Moreover, the last contribution is to provide a Lean Design definition while considering the aforementioned, and which could prove to be a valuable resource for researchers in the field.

Additional Information

For more information on this research, please read the following research paper: Chbaly, H.; Forgues, D.; Ben Rajeb, s. 2019. “Lean Design in Construction Industry: from Theory to Practice” presented at the CSCE Annual Conference, Laval, June 12-15 2019.