Those familiar with the application of lean principles have come across terms like: lean manufacturing, lean enterprise and lean organization. But lean maintenance is not as commonly discussed as the other three terms. Why is that?
Some consider lean maintenance as merely a subset or spin-off of lean manufacturing. In reality, however, that is not the case. Lean maintenance is actually a precondition for the success of lean manufacturing, rather than just an accessory.
This article explains the basic fundamentals of lean maintenance and presents a few of its benefits and challenges.
What Is Lean Maintenance?
Lean maintenance is a management strategy that aims to apply lean principles and goals to physical asset management.
The ultimate goal of lean thinking is to provide perfect value to the customer through processes that generate zero waste. In this context, waste refers to the use of resources (e.g., time, labor, inventory, energy, etc.) in any way that does not add value to the final product or service.
By applying these same lean goals, lean maintenance results in improved productivity and reduced costs, while also relying heavily on practices inherent in total productive maintenance (TPM) and reliability-centered maintenance (RCM) to be effective.
Foundational Elements of Lean Maintenance
It’s easy to understand why many still wrongly classify lean maintenance as a subset of lean manufacturing. After all, many of the tools used to implement and sustain lean manufacturing also apply to lean maintenance.
These tools form the foundation of lean maintenance and include:
The 5S Process
5s refers to five activities for organizing the workplace. When implemented, they deliver improved overall efficiency, storage and maintenance. Each “S” is a Japanese word that means:
Sort (Seiri) – Sort through the items at a location and remove any unnecessary objects. This improves safety and reduces the time spent looking for what’s needed.
Set in order (Seiton) – Rearrange the workplace so needed items are stored optimally and are easy to find.
Shine (Seiso) – Sweep, clean and inspect the workplace and any machinery. This prevents deterioration, improves safety and creates a pleasant environment.
Standardize (Seiketsu) – Establish schedules and procedures for repeating the first three “S” activities.
Sustain (Shitsuke) – Also described as “do without being told.” At this stage, workers are self-disciplined enough to continue and sustain the improvement process without continuously being told what to do.
Just in Time (JIT)
Just in time is a concept commonly used in reference to inventory. Companies use this strategy to reduce waste during the production process by receiving goods into their stock only when needed.
In lean maintenance, operators aim to predict repairs as accurately as possible. Repairs should never be done too soon or too late and all necessary spare parts should be available when due. In other words, monitor equipment and purchase parts “just in time” for the next maintenance task.
Elimination of the Seven Deadly Wastes
Reduce the steps in the process that add no value by eliminating the seven deadly wastes or “TIM WOOD.”
Transportation – Moving items and tools from one place to another unnecessarily.
Inventory – Allowing activities, such as work orders and job requests, to pile up.
Motion – Undesirable and avoidable movement due to poor workplace design and layout.
Waiting – Delays and idle time as a result of downtime, parts shortage, slow approval, etc.
Overprocessing – Doing work that the customer will not pay for or does not require.
Overproduction – Producing more than the required quantity of a good “just in case.”
Defects (Rework) – Resources wasted while correcting repair or servicing mistakes.
Total Productive Maintenance (TPM)
Total productive maintenance is a hands-on, system-wide and proactive approach to maintenance that lies at the very root of lean maintenance. Ideally, TPM should be already implemented and operational before an organization makes plans to adopt and sustain lean maintenance.
Take one of the pillars of TPM, autonomous maintenance, for instance. From top to bottom of the organization, every employee is involved in carrying out routine maintenance on the physical assets they operate daily.
By so doing, the enterprise enjoys the benefits of having a team of multiskilled technicians, operators and executives all working together to limit incidents of loss, breakdowns and other inconveniences.
Reliability-Centered Maintenance (RCM)
Reliability-centered maintenance is another proactive maintenance strategy used to monitor physical assets in their present operating condition and predict their maintenance requirements.
Since statistics indicate that about 70 percent of equipment failures are self-induced, maintenance engineers need to discover the causes of these failures. Thereafter, they can recommend preventive maintenance actions.
Planning for Lean Maintenance
The following items can help guide the preparatory stages for implementing lean maintenance.
- Proactive maintenance: Proactive, rather than reactive, maintenance should be already in place and operational.
- A work order system: This would capture all work assigned with details about maintenance schedules and job status. When managed within a computerized maintenance management system (CMMS), work orders are invaluable for quick access to information, especially equipment history.
- A CMMS: As a minimum, a CMMS should perform the following functions: budget and cost, work order management, planning and scheduling, spares management, reporting and labor management.
- An updated asset inventory: This will help ensure that no machine is overlooked during maintenance planning.
- Training and empowerment of operators: Both are required before handing over machines to them. Training and empowerment should be thoroughly exhausted as part of TPM implementation.
A Few Benefits of Lean Maintenance
Implementing lean maintenance delivers numerous benefits. Among them are:
Avoiding waste – A typical example is using the JIT concept to avoid keeping expensive inventory longer than necessary.
Reducing inefficient activities – Inefficient activities include running around looking for tools and shutting down equipment for maintenance without ensuring the resources for servicing are available beforehand.
Eliminating urgency – Frantic and urgent repairs are reduced to the barest minimum.
Minimizing the cost of maintenance – When the shutdown of critical equipment for maintenance is well planned, it reduces the amount of production time lost.
Common Challenges with Using Lean Maintenance
Organizations typically face two main challenges when implementing a lean maintenance strategy.
The first is expense. The up-front costs of some aspects of lean maintenance, for example implementing RCM, may be considerable. As such, it will take some time before reaping the benefits.
The second challenge is resistance to change. Some resistance to the new way of doing things should be expected. However, this resistance has to be carefully managed to ensure success of the entire process.
Lean maintenance and the benefits it promises are achievable. But, there is significant preparation that should be in place beforehand so it doesn’t become another wasted endeavor.
A major part of that preparation should focus on adopting the TPM and RCM culture well in advance before attempting to apply lean maintenance.