When it comes to TPM and Lean Manufacturing, there is a divide among Continuous Improvement professionals as to which is subordinate to the other. What I’ve found is that whichever approach you have built proficiency in first becomes the parent; meanwhile, the later becomes the child. However, there’s quite a bit more to the story. Both methods seek to minimize operating losses. They also help reduce cost while maximizing productivity. This article presents both sides of the coin to determine the difference between TPM and Lean Manufacturing in order to help you decide which approach would yield better results in your specific case.
What is TPM?
TPM or Total Productive Maintenance is a prescribed set of methods designed for sustaining a manufacturing system in peak operating condition. The objective is to eliminate waste caused by equipment and process failures. TPM uses Overall Equipment Effectiveness (OEE) as its primary measure of performance. It seeks to increase OEE by eliminating the 6 big losses, which include:
– Equipment Failures
– Setups and Adjustments
– Idling and Minor Stops
– Reduced Speed
– Process Defects
– Reduced Yield
TPM is made up of 8 pillars, which loosely mirror the departmental functions that you typically see in a manufacturing setting. This includes:
- Autonomous Maintenance Pillar – Operations Function
- Planned Maintenance Pillar – Maintenance Function
- Training and Qualifications Pillar – Human Resources Function
- Early Management Pillar – Engineering Function
- Focused Improvement Pillar ~ Industrial Engineering Function
- Safety, Health, and Environment Pillar – Safety, Health, and Environmental Function
- Administrative & Office TPM Pillar – Admin Support Function
- Quality Management Pillar – Quality Control Function
Each pillar contains a set of principles that set standards for how each of how the functions should be managed in order to achieve a sustaining state of peak operations. The ideal state would be absolute predictability of manufacturing results with as few planned losses as necessary.
What is Lean Manufacturing?
Lean Manufacturing is an approach to maximizing value to the customer, or end user. It looks at the entire supply chain from end to end to determine which steps actually produce value as perceived by the customer. Then Lean seeks to gradually eliminate all other, non-value-added, steps. There are 8 wastes associated with Lean methodology:
- Defects – products that don’t meet customer specification
- Overproduction – making more than what is currently being demanded
- Waiting – idle time
- Non-utilized Talent and Ideas – talent and ideas that are not being used to their potential
- Transporting – moving product from one place to another
- Inventory – idle product
- Motion – movement that occurs as a result of completing a task
- Excessive Processing – processing that exceeds what the customer requires
Toyota, regarded as one of the Leanest companies in the world, has famously stated that 93% of it’s value stream is waste, or non-value-added activity. This points to the incredible opportunity for improvement that exists when looking at the enterprise through the Lean perspective.
TPM as the Parent
Those who are die-hards for TPM will tell you that Lean is a sub-set that is captured within the Focused Improvement pillar. Since most of the TPM pillars are designed to eliminate losses in an established production system, they fit squarely within the category of a world-class maintenance program. However, the objective of the Focused Improvement pillar is to make incremental changes to the existing process so that it becomes a new process entirely, for which all other pillars need to be updated accordingly. For example, if an operator replaced a taller piston in a filler machine for a shorter one as part of an improvement project, the planned maintenance for the new shorter piston would need to be updated as well to reflect the change. TPM people would place many Lean tools such as JIT, Kaizen, Poke-a-yoke, SMED, etc within the Focused Improvement Pillar.
Lean as the Parent
Lean is more of a customer-focused, market-driven approach to Continuous Improvement. Pure Lean enthusiasts will tell you that TPM is a sub-set of Lean. They will say that TPM is a later step in the Lean journey that comes after the value stream as a whole has been sufficiently optimized for current market conditions. A true Lean thinker might look at the entire supply chain to determine optimal locations for manufacturing facilities. They would also look at the ideal flow of material through those facilities, processing activity, product design, and many other factors to minimize the 8 wastes. Once these key attributes have been implemented, the Lean thinker might deploy TPM as a means to fine-tune the remaining production process. However, since the customer’s perception of value is always changing, the Lean thinker routinely challenges rather or not the existing process sufficiently satisfies demand. There is a threshold of misalignment that justifies re-configuring an entire supply chain or part of the value stream to stay ahead of where the market is going.
Upon reading this, you might be wondering which approach makes more sense for you. In my analysis, the best approach is probably a combination of both methods to varying degrees of predominance. If you are in more of a market-driven business like many CPG companies, you will probably be more more apt to apply Lean as a predominate approach to Continuous Improvement with some key aspects of TPM. This is because the market shifts at a faster pace; therefore, you could get left behind if your value streams are incapable of flexing accordingly. However, if you are in a manufacturer-driven industry such as automotive, especially one where machines do most of the value-added work, you might apply TPM as your predominant approach to Continuous Improvement with some key aspects of Lean Manufacturing. In these industries, the speed of change in the market is much slower, therefore teams have more time to develop the level of process ownership required for proficiency in TPM. While a TPM person might be asking “how can we eliminate more losses from our process?”, a Lean person would be asking “is this process even needed in order to maximize value to the customer?” and if yes, “how can we apply TPM to eliminate losses?”