Many plants strive to increase the efficiency of maintenance craftspeople, but find it hard to identify where to focus efforts and how to track progress. This is not surprising given that the actual measurement of craft efficiency is not well understood. Efficiency measures should cover far more than utilization percentages for maintenance craft. This article outlines aspects of a more holistic measure of efficiency and effectiveness.
The proper measurement of maintenance craft productivity depends upon the use of sound planning and scheduling techniques. Application of such techniques is an essential preliminary to establishing a measurement system. So, let’s start with a brief overview of the connection between the planning and scheduling function and productivity measurement and reporting.
Planning, scheduling and productivity
Good work-order planning provides one of the most effective tools to manage maintenance activities. Several surveys indicate that efficient work-order planning can yield savings of 10-35% of a total maintenance budget.
Improved planning and scheduling techniques provide the means for working “smarter, not harder” and the mechanism for increasing productivity. Today, within industrial facilities in the U.S., craft utilization typically averages ∼32-35%. This can be greatly improved by developing more-efficient methods of accomplishing maintenance tasks. Job plans must be constructed to minimize wasted effort and constant review and study of planning history will reveal opportunities to reduce waste within these plans. Likewise, an effective scheduling system can considerably decrease non-productive time. Providing a schedule of work orders with job descriptions, material requirements, location of work to be done, etc., enables maintenance crews to spend more time on direct, hands-on activities and accomplish more work.
Typical planning-and-scheduling performance reports detail planned versus actual work in terms of hours, task durations, material usage requirements or budgeted dollars. These reports provide several indicators that can be used for measuring and comparing the performance of individual maintenance crews as well as the maintenance function as a whole against maintenance objectives. Typical indicators include:
• direct activity (wrench time);
• planned and emergency work percentages;
• schedule compliance;
• planned versus unplanned work; and
• planned material usage.
These planning-and-scheduling processes and data indicators provide a good framework for determining the current state of craft efficiency and productivity. However, these indicators alone do not give a full understanding of overall efficiencies and effectiveness within the maintenance system, and offer only limited opportunities for identifying optimal strategies to drive productivity and cost improvements. For this purpose, we need to delve deeper into the structural elements that define the measure of productivity and its subcomponents.
Productivity of personnel is defined as the amount of work actually done per paid hour and is further refined to include the amount of labor required to perform direct work without any losses in efficiency or effectiveness.
Overall productivity in the broad sense refers to all activities and functions necessary to complete a task and the efficiency and effectiveness with which that work is performed. It includes elements such as travel time to the job site, picking up material(s) from supply, preparing the area or equipment for work, job performance efficiency, the resulting quality of workmanship and all other indirect activities. Therefore, the measure of productivity needs to account for all of the efficiency and effectiveness losses that can limit the amount of work done in a period of time. This requires assessing three elements:
1. Direct utilization — the percent of time craftspeople are performing direct work.
2. Direct productivity — the actual units of work completed per hour as a percentage of a standard.
3. Rework — the percentage of work performed that must be redone.
Craft productivity then can be calculated as:
Productivity = (Direct Utilization)/(Target Value) × Direct Productivity × (100% - Rework)
Let us define and examine these three key elements of productivity to better understand their input to the measure and methods that may be used to improve individual elements.
This is the percentage of time technicians spend on the actual execution of a maintenance task, what often is referred to as “wrench time.” It contrasts with indirect activity — job preparation, travel, gathering materials, personal time (breaks, visits to the rest room, etc.), late starts or early quits, idle time and waiting for instructions or access to equipment. Hence, it is the percentage of direct versus indirect time or the actual performance of value added activity, with tools in hand, without inclusion of time losses due to planning, waiting, travel and logistics.
Time losses fall into two categories:
• Inherent losses — the minimum time requirements related to travel and logistics, assuming pre-planning and preparations for work are complete and without error.
• Planning losses — all other time requirements beyond direct utilization and inherent losses.
Direct utilization can best be measured through the application of labor activity analysis (LAA), a proven technique long applied to operations tasks. It can easily be adapted to any type of labor analysis including craft utilization. An LAA involves the random sampling of work activity being done in an area and then measuring and classifying the activity into categories of direct, delay and support activities (Figure 1). Direct activities include those of a typical wrench-time calculation while the delay and support activities are losses that reduce the percentage of direct activity for the observed timeframe.