Maintenance Management as a Quality Process
By Jeffrey Lewis
Maintenance practices and technologies have evolved to meet the needs of the changing industrial environment. The function has evolved from a community of reactive fixers, to dedicated craftsmen, to proactive professionals. The next generation of personnel could well be based on practitioners of Quality Management Systems (QMS).
Maintenance progress can be best demonstrated by its ability provide assurances for reliability. The model for quality Assurance, which meets the same requirements for Equipment Reliability, is demonstrated in the ISO 9001:2000 Standard, through process-centeredness.
Process-centered management is a system that manages organizational activities as a process. The process is managed through QMS, which is clear on PDCA as a process method. PDCA is Plan, Do, Check Act. Most modern maintenance management activities are not linked to QMS, which have particular management characteristics. Using these characteristics transforms modern maintenance practice into what may be the next generation of maintenance management. The structure of maintenance management as a process model is significant, as an International Standard to adopt as a relevant Standard or best practice for maintenance management's thrust towards reliability.
However, in order to resolve elements of the process the applicable definitions must addressed in order to provide the basis for generating reliability.
Maintenance can be defined as the degradation management of engineered materials (equipment and systems) to retain their performance within their designed operating parameters.
Just as stress can accelerate deterioration of metals in a corrosive environment, operational stress moves equipment and systems toward failure. Limiting stresses within the operating environment maintains reliability.
The elements of the maintenance which are relevant to PDCA are
- Protecting components from stress
- Monitoring their condition, and
- Undertaking component(s) replacement prior to the failure threshold level caused by stress excesses.
The components of this system are preventive maintenance (PM), condition monitoring (CM), and planned overhaul(PO). It is against this background that maintenance activities are identified.
Preventive maintenance is whatever action is undertaken to provide protection against or reduce the rate of degradation by:
- The application of coatings, adjustments, or cleaning to retain components within design operating conditions.
- The physical or chemical control of applied media to the operating environment, which has the potential to increase the stress in components beyond their design operating parameters.
- Condition monitoring identifies the adequacy of preventive maintenance for the stresses of the environment.
- Condition monitoring identifies the rate of degradation towards the failure threshold level.
- Condition monitoring is measurement of degradation or the rate of degradation.
Condition monitoring plays a dual role in the maintenance process for regulating preventive maintenance applications and, as stress increases, alerting to impending failure. (Another school thought is that condition monitoring is sometimes viewed not as a part of the maintenance process, but merely as a provider of process measurement for the "check' activity of the process.)
Planned Overhaul (PO)
Planned overhaul takes place prior to failure, when the rate of degradation is excessive as noted by condition monitoring, and the component(s) is approaching the threshold failure level. It involves the disassembly, component replacement, and re-assembly of equipment.
The maintenance attributes of PMs CMs and POs, is repeatable for equipment as it goes through its life cycle.
The characteristics of Quality Management Systems QMS are as follows as it applies to maintenance:
The 'Plan' to achieve reliability is based within the context of PMs, CMs and OH at the component level, while defining through documentation, the human, economic and technical resources to achieve the reliability.
The 'Do' is the actual work instructions to be performed and the options at the point of execution for informing of the requirements and record keeping of its reliability status.
The 'Check' is the means to identify whether the reliability requirements are being met within the context of the human, economic and technical resources.
The measurement of efficiency and effectiveness of the plan determines whether waste through errors or unwanted activity has occurred. It can track the use of resources to determine when they are beyond those proposed by the plan for reliability. Condition monitoring techniques are also applied as relevant measurements toward assured reliability.
These measurement parameters provide the trigger at the analysis stage to determine the component status for likely improvements toward reliability. In addition, the utilization of Pareto Analysis based on formatting root causes by harsh environment, improper operation, recommended end of life or lack of maintenance, will resolve improvement issues required for efficient and effective maintenance management.
The 'Act' is any action taken as a result of checking to provide the feedback mechanisms to the Plan for adjusting any of the PMs, CMs, or POs to ultimately reach the reliability levels required with the context the stated resources.
The application of the PDCA process above contains the characteristics of all Quality Management Systems, which provides performance assurances or reliability:
- Record keeping
- Procedures / Work Instructions
- Resource Identification
Maintenance Management systems with these characteristics provides the methodology for continual improvement towards intended reliability.
The adoption of the QMS model for maintenance has a number of advantages. The model:
- Identifies maintenance resources, as it facilitates its contribution (cash flows, current ratios, etc.) to enhanced organizational management.
- Represents the opportunity for maintenance to adopt similar process centered-ness, as the rest of the organization, in the event QMS forms part of the management of the organization.
- Determines the lowest cost of reliability proactively. Establishes a methodology for the best practices for Reliability.
- Establishes the selection basis for computerized maintenance management systems.
- Develops zero-based or activity budgets for maintenance; the lowest cost for reliability is measurable and variances can be addressed.
- Establishes a process through QMS for treating maintenance management
- Channels differing methodologies used by maintenance professionals into a world-class standard.
- Establishes a structure and accountability for measuring outsourced maintenance contracting.
- Establishes a method for determining maintenance human resource requirements where reliability assurances can be achieved.
- Defines the specific technical requirements for reliability.
- Establishes the basis for just-in-time (JIT) spares inventory management.
- Determines a methodical application of condition monitoring data and its role in the process.
- Identifies a parallel costing system for maintenance. Provides the basis for proactively establishing the contribution of maintenance to product cost.
- Develops root cause analysis for Pareto Analysis for continuous improvement
The ISO 9001: 2000 Scope is customer focused with respect to the effective application of the QMS system. The context is relevant as the operations / production department can be seen as the customer of the maintenance department. Promoting reliability through an improvement process, driven by the characteristics of QMS maintenance management, meets the requirements for the International Standard.
Finally TPM, CBM, RCM etc may very well have the same attributes as QMS, the aim should be for the maintenance community to dovetail all into one Standard for the practice of maintenance management. They all have the same objective of reliability - align them to the Internationally recognized QMS Standard and the egos of 'ownership' and which is better, can go away.