The methodological approaches advocated by Lean management are operational in nature and embody a philosophy of continuous improvement, active participation, and accountability through Lean thinking, aimed at reducing resource waste in favor of increased production. According to Womack and Jones (2021), Lean Management is grounded in five distinct key principles:
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Definition of Value:
identifying value from the customer's perspective, focusing on customer satisfaction as the ultimate goal. Identifying what the customer is willing to pay for allows the concentration of resources only on what truly matters, reducing waste. -
Value Stream Identification:
analyzing the value stream for each product, identifying and reducing waste from the design phase and effectively managing information throughout the entire production process. Value stream analysis can reveal activities that create value, activities that do not create value but are essential, and activities that can be eliminated as they neither create value nor are essential.
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Continuous Flow:
ensuring an uninterrupted flow of value, avoiding queues and batch processing during product manufacturing to improve not only quantity but also the quality of the process. The key and main challenge to achieve this flow is to ignore the boundaries between functional departments, which lead to the subdivision of activities into batches. The old way of thinking in terms of batches always results in waiting waste, as a product remains idle until the next departmental operation is ready. To achieve continuous flow, interdisciplinary teams focused on the entire value stream are necessary.
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Pull System:
organizing production and supply based on market demands, translating into avoiding overproduction and responding to customer needs promptly and efficiently. A basic definition of pull and its opposite, push systems, is provided by Spearman, Woodruff, and Hopp (1990). They define push systems as those where production orders are planned, while pull systems are those where the start of a job is triggered by the completion of another. The underlying assumption is that demand forecasts are always inaccurate, so it is a better approach to effectively respond to actual demand rather than anticipate it. The Pull approach allows adjusting production to actual demand, reducing waste associated with excessive production.
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Pursuing Perfection - Kaizen:
the Kaizen principle emphasizes the importance of continuous improvement. Involving all employees in constantly identifying and implementing improvements contributes to creating an environment where innovation is continuous. The focus is on gradual and constant growth, rather than drastic improvements in isolated instances.
Monitoring takt time is important to calculate the production pace and stay in line with customer-requested timelines without interrupting the flow. Takt time is based on a simple calculation dividing the total available time (counted in days) by the number of products required by the customer during the same period. After calculating takt time, checks include machinery efficiency compared to production forecasts and the congruence of the workforce with estimates. An excessive number of resources will lead to waste, while too few may cause production instability.
Thanks to these five key principles of Lean Management, organizations can optimize their processes, reduce inefficiencies, and simultaneously better meet customer expectations. However, as previously emphasized, Lean is a philosophy, a way of thinking and being that, to show real benefits, must but integrated into the company starting from the shared values that prioritize individual well-being instead of being exploited as a mere tool.