An Application of Lean Thinking to the Furniture Engineering Process

Efficient engineering processes are critically important for furniture manufacturers. Engineering impacts the production cost, design quality, product lead time, and customer satisfaction. This research presents a systematic approach to analyze a furniture engineering process through a case study. The research was conducted through a case study in a furniture plant located in China, producing American style furniture products. The first stage was to investigate the company's current engineering process, identify non value-added activities, and analyze the engineering performance based on selected Key Performance Indicators (KPIs) such as lead time, document error rate, and engineering throughput. A survey questionnaire was sent out to the engineering group to determine the current engineering efficiency.

Results show that "product complexity" and "engineer competency" are the two most influential factors that impact engineering lead time and quality. In the second stage, value stream mapping was used to analyze an upholstery furniture engineering process. The approach encompasses an analysis of the current state of the engineering process and the proposal of a lean future state value stream map (VSM).

Results from the current state VSM show, that the value-added ratio of the current engineering process is only 26%. Several engineering steps present deficiency such as the processes of creating drawings, compile mass production documents, check and sign-off engineering documents, create CNC programs, and generate packaging files. Based on current state VSM analysis, the researcher focused on transforming these processes to eliminate waste and to propose the best practices for the future state VSM.

From this research, it shows that current processes include a large amount of non-value adding activities such as waiting, extra processing, rework, excess motion, transportation, underutilized people, and inefficient information. These non-value adding activities are interfering with engineers' ability to prepare engineering documents for downstream jobs and affecting the overall manufacturing process. The VSM is effective to provide the visual control over the engineering process for implementing lean transformations.