For a cement manufacturer to maximise its profits, it needs to maximise the quantity of clinker and cement that it can produce at the lowest possible cost of production for its particular location and market. Whilst this may seem an obvious statement, it is not always the case that cement manufacturers achieve this. Optimisation of cement manufacture is achieved by ensuring that:
- The throughput of the plant is as close to the design capacity on a consistent basis, without pushing the plant to the extreme such that the equipment life is cut short.
- The plant runs for as many hours as possible through the year and is stopped for annual maintenance as planned.
Many companies have adapted their engineering departments to become focused upon reliability instead of maintenance. This entails predicting a failure before it happens and taking the corrective repair/replacement prior to failure, as opposed to waiting for a failure to happen and then fixing it. Taking this approach involves restructuring the engineering department resources to include different roles, using computerised maintenance management systems, improving planning and procurement and using modern maintenance tools and techniques.
At this point, it is useful to consider that maintenance is about keeping constant whereas reliability is about continuous improvement.
Reliability department structure
One of the most fundamental changes required is the creation of a number of new functions within the engineering department. Traditionally, the engineering department is made up of a number of engineers and a group of mechanical and electrical craftsmen. The workload is planned by the engineers – generally based upon the previous day’s breakdowns and planned routine maintenance. However, often the daily plan is disrupted by events of the previous night; work is rescheduled onto the highest priority job and the planned maintenance would be dropped. This results in wasted time as resources are switched from one job to another, as well as when the correct tools and spare parts are organised for the new jobs. In addition to this wasted time, a backlog of the planned work builds up, which can tend to result in additional plant failures.
Within a reliability department, a number of new roles are created focused upon ensuring that the state of the equipment is correctly monitored and that maintenance activities are fully planned so that the reliability of the plant improves and the maintenance costs are reduced. It could be said that moving from a maintenance culture to a reliability culture is all about moving from a reactive to proactive manner of maintenance. The specific roles that are created within the reliability department are detailed below.
The role of the inspector is as would be expected – to inspect the equipment within a specific area of the plant. There are two types of inspections carried out – first level inspections and specific inspections. First level inspections, which can be undertaken with or without the equipment running, rely upon the four senses of the inspector and usually take place on a general walk-through of the plant area.
The other types of inspections are specific inspections. In this case, measurements are taken and results recorded to enable trends to be established and accurate predictions about the equipment life to be made.
The purpose of the inspectors is to provide up-to-date knowledge of the plant condition (so that a history of the plant can be maintained), to assess when equipment is approaching failure and to raise work orders for necessary repairs/replacements of equipment. One of the key roles for the inspectors is to determine the type and frequency of inspection required for different pieces of equipment and ensure that records of the inspections are kept.
Again, the name of the planner describes exactly what their specific task is – planning the workload for the craftsmen within the engineering department. Once the inspections have been carried out it is the planner’s role to ensure all the preparation needed for the job to progress to the craftsmen is complete. During this phase, the success of the reliability strategy is tested, as it is now that spare parts required, time to complete the work and numbers of people needed are identified. Better planning enables the plant to make fuller use of the labour.
The planner works on two plans – the day-to-day planning of the repairs to the plant, as well as the plan for the annual repair. Planning for any future major repair should be started as soon as the current major repair has been completed. The planning department should measure its performance by comparing the percentage of work that is completed as planned and scheduled against pre-defined targets.
The reliability department should also include a dedicated lubrication department and a drawing office department. The implementation of the change of department structure requires careful planning, ensuring that the correct people with the willingness to learn the new role (especially the inspectors) are selected. Training may be required for many of the personnel and it is essential that all of the plant employees understand the role and objectives of the department.
Part 1 of 2. Find part 2 here.
Written by Mark Mutter, Jamcem Consulting, UK. This is an abridged version of the full article, which appeared in the September 2013 issue of World Cement. Subscribers can view the full article by logging in.
Read the article online at: https://www.worldcement.com/europe-cis/29082013/managing_for_reliability_jamcem_part_1_cement_126/