Evolving to preventative plant maintenance

Phil Burge, Marketing Manager at SKF, reviews the latest developments in the evolution of preventative plant maintenance, which are enabling engineers to minimise costs while optimising plant productivity.

Luton, UK - Plant maintenance has evolved considerably over the years, with a largely reactive approach giving way to time-based preventative strategies and, more recently, one that is driven by the condition of equipment. An increasing range of diagnostic tools and software has made it possible for engineers to monitor machine performance closely and, as a result, manage the frequency and type of maintenance carried out in order to achieve optimum performance across the plant.

While, in the past, maintenance has all too often been viewed as an expensive necessity, requiring skilled labour and machine downtime, there has recently been a shift in perception, with managers now clearly aware of the opportunity that exists to maximise profits through an effective maintenance strategy. However, with so much condition monitoring technology now available, there is often confusion surrounding the best way to approach the maintenance requirements of a plant and equipment.

Perhaps the most important factor to take into account is the need for a structured plant wide framework that ensures maintenance processes are approached in the most effective way across all areas of the business. Although a series of individual maintenance strategies carried out in departmental isolation may have a noticeable effect on a company’s bottom line, the results will be limited and maintenance costs will remain reasonably high. A far more effective proposition is the implementation of a holistic strategy that enables an organisation to synchronise its operations.

A solution of this type, which takes into account the needs of an entire company, allows maintenance issues to be assessed, analysed and managed simultaneously. In doing so, managers are able to minimise costs through maximising the efficiency of maintenance procedures, while achieving consistently high levels of uptime and productivity.

The latest integrated plant maintenance strategy frameworks offered by leading engineering companies are designed to enable companies to manage their assets more effectively, ensuring that their plant runs as smoothly as possible with minimum downtime. The considerable increases in profitability that these solutions offer are made possible through enabling the same output to be produced for less cost or increased output for the same cost.

A successful holistic plant strategy must encompass everything from top-level business planning, system-wide analysis and, crucially, must also include a shift from largely reactive repairs to an optimised mix of planned, predictive maintenance; this evolution needs to be sustainable in the long term in order to generate the most beneficial results. Although these approaches, by their nature, take the requirements of a whole plant into account, the specific maintenance needs of individual pieces of equipment are also analysed separately to ensure they are consistently delivering optimum performance and maximum uptime.

For senior plant engineers to identify the root cause of machine failures and pro-actively plan corrections and upgrades to equipment and maintenance programmes, asset information must be collected and used effectively. There are a wide range of instruments and analytical software packages now available to facilitate these processes, simplifying effective plant-wide communication between machine operators, maintenance and management teams, and allowing informed decisions to be made.

Capturing and documenting both current and historical data on an organisation’s assets is a key component of a successful asset management programme; this information can enable the organisation to balance maximum performance and minimal timely maintenance to achieve its cost and production goals.

By integrating condition based maintenance programmes into a single overall strategy, increased mean time between failures (MTBF) can be achieved and, as a result, a significantly lower cost of ownership. With the latest advanced condition monitoring processes, machine vibration and wear levels can be reduced, extending the service life of plant assets, and minimising the frequency of unplanned downtime.

SKF, for example, has developed an approach, which incorporates four key elements: maintenance strategy, work identification, work control, and work execution. Although all four elements should ideally be carried out simultaneously for maximum effect, the individual stages can be approached consecutively if time, money or resource constraints apply.

The first process in the programme, maintenance strategy, is the stage at which a business sets out its larger goals and objectives, assesses plant criticality and risk, and decides what the most important issues and priorities are. This is essential for a suitable and effective maintenance plan to be created, and sets in place a recognised and auditable company asset management strategy, which can be easily communicated throughout an organisation.

This information can then be used in the second stage, work identification, where critical plant information is gathered and analysed, allowing informed decisions to be made and the corrective maintenance operations to be carried out. At this stage an industrial Decision Support System (iDSS) can provide valuable support to senior maintenance engineers, by making available online relevant condition-based maintenance recommendations, as well as access to a specific expert knowledge on asset maintenance. Work requests can then be submitted to a Computerised Maintenance Management System (CMMS), to be combined with other pre-determined planned and corrective maintenance activities.

The third stage, work control, relies heavily on the priorities and structure determined during stages one and two, allowing maintenance activity to be planned in detail and scheduled, with tasks prioritised, taking into account timescales, man-hours required, data feedback, and competence requirements. Effective planning at this stage, combined with good spares management, well-defined job plans and trained staff, allows resources to be utilised in the most efficient and productive way.

With these three components fully realised, the final stage, work execution, can be implemented, with detailed plans put into action and maintenance work being done. It is crucial that feedback is collected via post-maintenance testing in order for continuous improvement to be maintained and maximum return on investment to be achieved.

In summary, implementing a holistic, inclusive approach to plant maintenance and asset optimisation is essential if companies are to reduce maintenance associated costs and minimise unexpected downtime. With effective lines of communication in place across all levels of the business, a sustainable approach to plant maintenance can be put in place that has a long term effect on the company’s profitability.