Lean maintenance has been erroneously thought to be a spin off or subset of lean manufacturing. What business managers failed to realize is that lean maintenance is actually a prerequisite for the success of lean manufacturing. It is an independent discipline under the broad concept of lean management or lean business operation.
Lean maintenance is proactive maintenance operation that employs scheduled and planned maintenance activities through total productive maintenance (TPM) practices utilizing strategies that were developed through the application of reliability centered maintenance (RCM) decision ideas and performed by self-directed action teams employing the lean management improvement principles as follows:
- Define value using the point of view of the end user.
- Identify every single step in the business process and discarding the steps that do not produce much value.
- Creating a tight sequence of the steps that create or produce value.
- Repeating all those steps on a progressive basis until all the wasteful steps are eliminated.
Lean maintenance could be explained and illustrated by way of some descriptions, illustration, and examples foremost of which are the following:
Proactive – Traditional maintenance operation is reactive. Maintenance operations react to equipment failure. Maintenance does not do anything until there is breakdown, making maintenance a misnomer because repair is never an equivalent of maintenance. In lean maintenance, proactive measures are taken to prevent equipment failures through predictive and preventive maintenance actions. The objective is to eliminate repair jobs by preventing equipment failures.
Planned and scheduled – Planned maintenance under lean maintenance calls for the use of established maintenance activities that identify maintenance steps, labor resources, materials and parts requirements, time allotment, and technical procedures. Scheduled maintenance calls for setting up of work priorities, issuing work order, assigning labor resources, assigning time period for the task performance, and the breakout and staging of the materials and parts.
Total productive maintenance (TPM) – It is the initiative for the optimization of the effectiveness and reliability of manufacturing equipment. It addresses the entire life cycle of the production system by building a solid, floor-based system that aims to prevent all kinds of losses. Total production maintenance also aims to eliminate all forms of breakdowns, defects, and accidents.
Reliability centered maintenance (RCM) – While TPM focuses on preventing breakdown by maintaining the effectiveness and reliability of the equipment, reliability centered maintenance is focused on optimizing the effectiveness of the maintenance tasks.
Empowered action teams – Activities of the action teams are focused on strong performance and are task-oriented. They are organized with the aim of performing integrated and whole tasks, and therefore requiring membership coming from multiple departments. The teams are granted autonomy in their administrative functions and members are granted participation in the selection of new members. Members of the teams possess multiple skills to enable them to adapt to unanticipated occurrences or events in the course of their work.
5S process – Improving and maintaining the work place involve five activities as follows:
- Sort or removal of unnecessary items
- Straighten or organize the work environment
- Scrub or clean everything in the work environment
- Spread or expand the maintenance process to other areas
Kaizen improvements – Kaizen is the philosophy behind lean management that calls for continuous improvement in the production process. It requires that each process be continuously evaluated and improved in terms of amount of time involved, resources utilized, result quality, and other aspects related to the process.
Maintenance statistics show that a big percentage of equipment breakdown are self-induced. A big responsibility of lean maintenance therefore involves discovering the causes of equipment failures. Equipment reliability engineering becomes a major concern.
Reliability engineering includes the following responsibilities:
- Evaluation of the effectiveness of preventive maintenance
- Development of predictive maintenance analysis system and procedure
- Conduct of condition monitoring and equipment testing
- Use of engineering techniques to augment the life of equipment
- Conduct of failed part analysis
- Problem recurrence control
Lean maintenance creates the environment required for an efficient and lean manufacturing process.