Value stream mapping with lean thinking model for effective non-value added identification, evaluation and solution processes

The effectiveness of the application of value stream mapping (VSM) highly relies on the analysis of current state mapping (CSM) that focuses on identification, evaluation and solution processes of the non-value added (NVA) activities. The conventional application of VSM is performed for these processes using the effect-based solution approach. Here, the effects of NVA activities (known as production waste), such as defects, lead time, bottlenecks, etc. are separately identified and evaluated before being related to Lean tools for solution. These tools then recommend ways to eliminate/minimize waste. This conventional approach, however, will lead to unstable solution for long term practice due to its mechanism in targeting the effect as a primary solution rather than the root cause of the effect. In the literature, there are very limited works highlighting these processes in systematic, practical and effective ways. Therefore, this paper introduces a methodology called the VSM-Lean Thinking (VSM-LT) model to improve the analysis of CSM. Then, guides a feasible solution identification before it can be visualized in future state mapping (FSM). The key idea behind this VSM-LT model is to identify and evaluate the root cause of the waste as revealed by CSM. The waste is then treated by solving the identified root cause(s) as a primary solution target. The model provides a chain-effect relationship mapping platform to identify and evaluate the root cause (s). It can be carried out based on four steps; NVA effect identification, LT-based operation features deficiency matching, possible root cause(s) mapping and solution identification & mechanism description. The model is then validated using a case study in a small medium enterprise (SME) of the food-based manufacturing industry. Validation results showed that multiple NVA activities visualized through CSM, come from one similar root cause. Therefore, feasible solution strategies and mechanisms are then recommended. Based on identified root causes, the FSM is then presented to visualize the improvement. Related measures of expected improvement are then compared. In overall, the proposed model is significantly beneficial for VSM practitioners to improve the analysis and evaluation of CSM towards identifying more sustainable solutions for their industry-based operational problems.

Automated summary

This paper introduces a methodology called the VSM-Lean Thinking (VSM-LT) model to improve the analysis of current state mapping (CSM) in value stream mapping (VSM). The model identifies and evaluates the root cause of waste revealed by CSM, providing a chain-effect mapping platform. It is validated using a case study and recommends feasible solution strategies and mechanisms.