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.
Calculating productivity
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.
Direct utilization
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.
Typically in organizations that do not use best practices for maintenance planning and scheduling, direct utilization only reaches ∼ approximately 20-30%. Organizations using best practices may achieve world-class performance of 50%. Therefore, it is useful to divide the direct utilization percentage acquired from the LAA by the world-class target value of 50% to obtain a normalized factor for our productivity calculation.
The measurement of activity in terms of direct, delay and support elements provides an excellent approach to track and continually focus and prioritize efforts. Improvements in direct utilization can be targeted once the loss areas are measured to identify those areas needing the most attention. These elements can then be re-measured in subsequent LAAs to track improvement and assess the impact of planning and scheduling functions within the organization.
Frequently, initial work-sampling results show improvement opportunities that are easily realized through better maintenance planning. Furthermore, lowering the percentage of indirect activity directly translates to opportunities for increased work output, which often results in enhanced equipment reliability.
Direct productivity
The percentage of actual direct time needed to perform a task versus the standard time for that task is direct productivity. The standard time represents how long an average skilled technician, working at normal pace, needs to perform a direct activity — using a prescribed method — without allowance for personal needs, fatigue and delays.
Time standards are common for most recurring tasks within operations. However, for purposes of maintenance craft calculations, standard times can best be determined as the expected time that was planned for the task. Therefore,
Direct Productivity = (Standard (Planned) Hours)/(Direct Hours) × 100%
A number of skill-improvement programs and motivational methods can be used to improve direct productivity. Such methods include specialized skills training, multi-crafting and multi-skilling of the workforce, modular designs for equipment removal and replacement, use of quick-disconnect fittings, special jig usage and pay-for-skills programs.
Rework
This is the amount of craft labor required to perform maintenance tasks a second time because of inadequate original work. Factors such as poor workmanship and use of the wrong materials or parts can mandate rework. Whatever the reason, rework reduces craft productivity and increases craft labor costs because time available for other activities is lost.
Conceptually, the effect of rework on overall productivity is easily understood but in practice rework can be a very difficult activity to measure. Usually it is only identified anecdotally during team discussions or planning meetings. However, for computational purposes rework can be fairly easily estimated if we assume that most repetitive maintenance tasks for the same equipment item over the course of a short time period (say, one month) stem from some error or omission by technicians. Given this assumption, rework can be estimated via a computerized maintenance management system (CMMS) report generator. The estimator can be calculated as follows:
Rework = (Total Craft Hours Other Than First Time for Each Piece of Equipment)/(Total Craft Hours in Period (month))
The measurement of rework can provide a focus for corrective actions. Losses can be categorized by cause, such as bad material, technician oversight, ineffective procedures, inadequate training, etc., and then corrective actions taken and their impact tracked. Typical corrective actions include assigning more-qualified personnel to certain tasks, developing job plans and procedures for repetitive work, adding equipment-specific training programs and identifying proper tools and equipment needed for tasks.
The overall calculation
With these structural elements and components defined, we now can combine our estimator for rework with our calculations for direct utilization and direct productivity to complete the calculation for overall craft productivity. Figure 2 summarizes the major elements of this calculation and common opportunities for improvement of each of the elements.
Most organizations do not measure many of these activities. However, those organizations that do the calculations and apply key corrective actions achieve top-quartile asset performance, and thus, significantly enhance their financial performance. Implementing the measures described in this paper should bolster productivity within your organization.
Timothy J. Finigan is Senior Director Performance Technology for Fluor, Greenville, S.C. E-mail him at [email protected].
