The Bradford Factor, typically used in human resources, can be a valuable tool for assessing how equipment downtime impacts fleet productivity, particularly in heavy-equipment contracting.
The effectiveness of fieldwork in this industry depends on two critical factors: the equipment and the personnel operating it. These elements are interconnected, with equipment relying on skilled operators, and operators relying on the equipment to perform their tasks. When either of these components is compromised, work in the field suffers.
In equipment management, various metrics like downtime, mean distance between failures, and availability are employed to ensure that equipment remains operational and ready to work. However, these metrics often focus solely on equipment performance and don’t account for the wider impact on operations, clients, or the organization as a whole when breakdowns and downtime occur. As a result, disputes arise, emotions run high, and additional metrics are introduced in an attempt to gain a more comprehensive understanding.
Is there an alternative that simplifies this situation? Is there a metric, well-established and documented in other fields that can effectively identify underperforming machinery without complicating business operations further?
One such metric, originally used in human resources, may offer a solution: the Bradford Factor. It was designed to quantify the impact of frequent, short-term employee absences on an organisation. The concept is based on the idea that recurrent, brief absences can disrupt a business more than longer, continuous absences.
The Bradford Factor formula
The Bradford Factor formula considers the number of absence instances and the total days absent. The formula is B = S^2 x D, where B represents the Bradford Factor score, S is the number of separate instances within a specified period, and D is the total number of days absent in the same period. Higher Bradford Factor scores suggest more disruptive absence patterns.
This metric can be adapted for equipment management. By defining “S” as the number of separate downtime events within a specified time frame and “D” as the total downtime days, you can use the Bradford Factor to assess equipment performance.
Here are three scenarios to illustrate how this would work:
- Equipment A experienced one downtime event for a total of 10 days over a 52-week period, resulting in a Bradford Factor of 10: (1 x 1) x 10.
- Equipment B had two downtime events, each lasting five days, over a 52-week period, resulting in a Bradford Factor of 40: (2 x 2) x 10.
- Equipment C had 10 downtime events, each lasting one day, over a 52-week period, resulting in a Bradford Factor of 1,000: (10 x 10) x 10.
These scenarios demonstrate that equipment with shorter, more frequent downtime events yields higher Bradford Factor scores, indicating a more significant negative impact on the organization.
In practice, equipment downtime often occurs on project sites where operational efficiency is critical. When equipment is down, it leads to production delays, schedule disruptions, increased costs, reduced profitability, and downstream impacts on return on investment.
Applying Bradford Factor to machinery management
To apply the formula to equipment management, you can compile data for your equipment fleet. The table below lists 10 dozers, detailing the number of downtime events (S) and downtime days (D) for each unit. The average days down as well as the Bradford Factor are calculated and placed in the columns to the right.
Unit D6007 had the highest number of down days and the highest average days down, while Unit D6003 had the second-highest average days down. But neither Unit D6007 nor D6003 are in the top five of the Bradford Factor.
This is because both units had infrequent and longer-term down periods, so their Bradford Factors were much lower than units that had more frequent and shorter down events. Although both of these units certainly have issues that need to be addressed, the results suggest that it was easier for the business to plan around the downtime of these two units.
Units D6005, D6009, and D6010 have the highest Bradford Factor scores even though their average down days are some of the lowest in the group. The magnitude of the scores suggest that it was harder for the business to plan around the downtime of these units. When the formula is employed, you can be absent frequently but not for long periods, and you can be absent for long periods but not frequently. A machine can be down frequently but not for long periods, or a machine can be down for long periods but not frequently.
Notably, units with infrequent but longer-term downtime events may have lower Bradford Factor scores, as it is easier for the business to plan around these instances. In contrast, units with frequent and shorter downtime events may have higher Bradford Factor scores, indicating that it was more challenging to adapt to their downtime.
A systematic approach
Using the Bradford Factor in equipment management provides a systematic approach to identifying underperforming equipment and aids decision-making regarding maintenance priorities.
The concept of applying the Bradford Factor to equipment management emerged during a seminar in Canada, where it was used to assess machine performance and identify problematic equipment. By aligning readily available data with the Bradford Factor (S being the number of repair work orders and D being the mechanic hours spent), the results closely matched the opinions of those who worked with the equipment daily.
This adaptation of the Bradford Factor offers a quantitative way to pinpoint underperforming equipment, aligning with intuitive assessments of their performance. As organizations strive for operational excellence, the Bradford Factor provides a concise and effective means to enhance maintenance decision-making.