Maintenance planning and scheduling is the process of identifying, prioritising and organising work so that it can be executed in the most efficient manner, says Deelip Prabhudesai.
One of the major problems faced by majority of the cement companies in India is frequent equipment failures. Repeated machinery breakdowns not only result in loss of production, but also create quality issues, increased maintenance costs, loss of customers and higher safety incidents. Reactive maintenance takes precedence over planed and proactive maintenance. As a result, health of the assets continues to deteriorate with continual decrease in throughput.
A simple yet most efficient, cost-effective and time-tested approach to eliminate such problems would be effective maintenance planning and scheduling. Unfortunately, a very high percentage of the cement companies in India haven´t yet realised the importance of this simple methodology. While a few have managed to introduce planning and scheduling in their plants, the quality and effectiveness of the process followed is far from satisfactory. In fact, the concept of planning has been grossly misunderstood. What is being practised by most of such companies in reality is more of scheduling rather than any real planning. Whatever planning and scheduling exists is restricted to shutdowns only, with majority of the other day-to-day maintenance activities being carried out on a reactive basis.
Getting it right
Maintenance planning and scheduling is the process of identifying, prioritising and organising work so that it can be executed in the most efficient manner. The principle revolves around getting the maintenance jobs done the right way using the right people with right tools, spares, services and information at the right place and right time. The term ´planning´ deals with what is to be done and how it is to be done. It involves detailed analysis of the work to be performed, sequencing of tasks involved, methods, drawings & schematics; resource requirements including craft, size of the crew, labour hours, tools, spares, materials, supporting equipment etc., along with permits, safety and statutory requirements.
Scheduling is who will do the work and when. It is the documented allocation of resources for each of the jobs to be performed in the specific week finalised in close agreement with the operations and materials departments. Once put in place, an effective planning and scheduling process ensures that all the maintenance work except emergency jobs is properly planned, scheduled and coordinated well in advance, to facilitate quality execution.
One of the immediate benefits of implementation of maintenance planning and scheduling is ´Wrench Time´ improvement. Wrench Time is defined as the actual time spent by a workman doing value-added work. The world class standard for Wrench Time is 60 per cent to 62 per cent. Unfortunately, this figure is dismal and often observed to be as low as 22 per cent to 32 per cent in most of the cement companies in India. It is easy to find a lot of time of the maintenance crew being lost in travelling, waiting and searching spares, tools, materials, permits, services etc. Thus even a 30-minute job often takes more than an hour or two to complete.
By following planned maintenance, the Wrench Time gets increased well over 50 per cent to 100 per cent of the current level within a span of 6 to 12 months. With increased Wrench Time, the maintenance execution team is able to carry out all the necessary corrective, predictive, preventive, modification and safety work as required in a time-bound manner. Consequently, there is a momentum shift from reactive to planned and proactive work culture with continuous reduction in asset failures.
As a thumb rule, emergency maintenance work costs 3 to 5 times and unplanned work costs 1.2 to 1.5 times the planned work.
With implementation of effective planning and scheduling, there is a continual drop in all the emergency and unplanned work resulting in 20 per cent to 30 per cent reduction in maintenance costs within 12 to 18 months.
Some of the major benefits of maintenance planning and scheduling are: