Nut Plant Maintenance Resource Center
Work Order Priorities
Join Now
FREE registration allows you to support this site and receive our regular M-News newsletter.

bkused120x60.gif - 3168 Bytes

Work Order Priorities

Author : Daryl Mather
Maintenance Consultant

Too many organisations neglect the benefits of a clearly defined prioritisation system. Even when they realise the importance the focus is invariably at a department or functional level. I have seen organisations where there are up to three or more prioritisation systems. None of which are inter-related.

Along with work order classification, failure coding and integration with business processes, this is one of the key determinants of a maintenance systems future operation. The drawbacks of not clearly defining the priorities, or defining them at a departmental level are many, they may include:

  • Wasted maintenance man-hours on tasks of low relative importance
  • Critical tasks being lost in the maintenance backlog
  • Dissatisfied operations customers
  • Lack of faith in the effectiveness of the maintenance delivery functions

A disciplined method of prioritisation will eradicate tasks being done on a whim and allow work to proceed according to its true effect on the overall operations of the plant. It will also allow the maintenance delivery function to be executed in a far more effective manner. For example while works orders of higher priority will remain those that are scheduled, to achieve the capacity scheduling limits set by the organisation, there will develop a pool of lesser priority tasks that can be attended to in an unscheduled manner. Giving a base for project type works for various craft disciplines.

System Guidelines

The system will need to cater to the following requirements equally and give a universal method of coding all works orders.

  • Site wide plant equipment priorities, allowing for better site wide direction of resources
  • Operations requirements
  • Improvement projects

Accurate prioritisation covers three distinct decision-making processes, although one may be preset the others will require a degree of judgement and lastly discretion in executing work orders practically.

  • Equipment Criticality
  • Effect of task or work to be done
  • Real world limitations on execution

Original priority of the work orders needs to be set by the originator of the work order.

This person is the most qualified to answer the questions of equipment criticality and effects of the task/fault noted.

Listings of major equipment and their criticalities will assist in decision-making, lower criticality items or areas will be easier to recognise.

The coding system listed below is an example of how to go about setting a "future proof" prioritisation system for work order coding. Although this can appear complex at first, once the required training, documentation and guidance are in place it becomes an integrated part of daily business processes.

The following criteria could be used to judge equipment criticality and effect of the works:

Equipment Criticality Description
1 Critical safety protective devices
2 Critical to entire plant operation
3 Critical to continued production of Main Product
4 Ancillary System to main production process
5 Critical to continued Production of Secondary Products
6 Ancillary System to secondary production process
7 Stand - by unit in a critical system
8 Stand by unit in a non critical system
9 Ancillary Equipment

Task Effect Description
A Immediate threat to safety of people.
B Immediate threat to the safety of the plant
C Limiting Operations ability to meet primary targets
D Limiting Operations ability to meet secondary targets
E Hazardous situation, people or machinery, not immediate
F Will effect operations after time
G Improve the efficiency of the production process
H Restoration of the plant technical integrity
I General improvement to further operability, safety or maintainability goals

The combination of the criticality and effect of the work can be cross-referenced to give a relative weight of each task in comparison to all other types of works. The colours represent the time frames with which these priority tasks can be allowed to occur.

Although open to debate the timeframes for work for work orders of varying priorities can generally be grouped into 5 or less. This allows for both criticality and effect of work and is to be a cross reference for all work order assignment.

  Effects of Task
1 1A 1B 1C 1D 1E 1F 1G 1H 1I
2 2A 2B 2C 2D 2E 2F 2G 2H 2I
3 3A 3B 3C 3D 3E 3F 3G 3H 3I
4 4A 4B 4C 4D 4E 4F 4G 4H 4I
5 5A 5B 5C 5D 5E 5F 5G 5H 5I
6 6A 6B 6C 6D 6E 6F 6G 6H 6I
7 7A 7B 7C 7D 7E 7F 7G 7H 7I
8 8A 8B 8C 8D 8E 8F 8G 8H 8I
9 9A 9B 9C 9D 9E 9F 9G 9H 9I

Time Frame Colour User Priority
24hrs   1
48hrs   2
72hrs   3
3 week   4
3 weeks +   5

As this is only a tool to reach the timeframes represented by the coding, the effects or equipment criticality rating can be changed to represent changes in corporate policy, planning windows or equipment requirements.

Planner Priority

In executing this work there will always be difficulties. These are associated with:

  • Labour shortages
  • Plant availability
  • Material lead times

To balance these items against the priorities of the plant as represented by the originator priorities, the planner requires a system of coding work orders to determine how they will practically be completed. The degree of flexibility needs to be built into the coding system.

This adds a third dimension to the prioritisation process and allows for the consideration of real world limitations on workflows. Including rapid changes to overall operations priority.

Although there are many recommended approaches to prioritisation, I would recommend this system as one that is suited to organisations where the maintenance function may cover various plants or ranges of equipment. As well it can easily be adapted if the organisation decides to re-structure itself. (As happens frequently)

No matter which approach is used without it the maintenance department cannot continually carry out its function with any degree of certainty.

For any further information regarding prioritising systems, or for information relating to any other basic aspect of maintenance planning or scheduling please feel free to contact me directly.

Daryl Mather

Copyright 1996-2009, The Plant Maintenance Resource Center . All Rights Reserved.
Revised: Thursday, 08-Oct-2015 11:54:59 AEDT
Privacy Policy