I was on a plane the other day, chatting with a high school soccer coach who happened to be sitting next to me. His excitement to talk about coaching seemed palpable, so I listened. He described an interesting difference between practice sessions and game day.
During routine practice sessions, players sometimes go through the motions while completing repetitive drills. However, when the stadium lights come on, the same players often play with remarkable precision. They hadn’t suddenly become different players; the spotlight simply changed their operational environment.
As I listened to the coach, I realized laboratories face a similar challenge. A proficiency sample is the laboratory equivalent of game day. But what happens if a laboratory prepares differently for the game than it does for practice? In a construction materials testing laboratory, this gap between routine operations and proficiency testing is a tightrope every manager must walk.
Daily practice represents the routine high-volume testing of aggregate and asphalt samples from various projects while game night represents the proficiency sample used to evaluate laboratory performance. The challenge comes from balancing two competing priorities: routine testing demands and mandatory compliance work. Like the soccer team, technicians are not necessarily underperforming because they lack discipline or competence. Instead, the shift in focus and attention can affect how they approach the task.
Although lab managers dread seeing low z-scores, they can provide valuable opportunity to identify hidden process weaknesses before they grow into larger problems and begin to affect accreditation. Repeated low ratings may ultimately result in the suspension of a laboratory’s credentials until the issues are resolved. Because the stakes are so high, the arrival of a proficiency sample box creates a major logistical crossroads.
Game Night Or Just Another Sample?
When a proficiency sample box arrives, the temptation to treat it as a high-stakes championship game is understandable. Laboratory managers are inclined to assign the work to a senior technician by clearing their schedule of all daily work and letting them focus only on the proficiency sample. This approach would likely result in a favorable z-score, but it may be capturing the laboratory’s optimized performance rather than normal operating capability.
The other option is to add the proficiency sample into the daily workflow along with the truckloads of samples waiting to be tested. This does not mean treating it casually. It means applying the same documented procedures, quality controls, and equipment requirements that should exist for every other sample tested in the laboratory. The difference is that technicians must work on proficiency samples while managing the daily demands of routine testing.
This choice of how the proficiency sample is handled raises an important question: what exactly is proficiency testing supposed to measure? Is it intended to demonstrate the laboratory’s absolute best performance under ideal conditions, or its ability to consistently produce reliable results through its established processes?
Why Low Scores Happen In A Busy Lab
When a low performance rating occurs in this everyday environment, it is rarely a sign of subpar work or technicians intentionally taking shortcuts. Instead, a low z-score may reflect the influence of normal operational conditions, competing deadlines, shared resources, workflow limitations, and so on.
A good example of this is a proficiency sample that may come with instructions to condition an asphalt mix sample in accordance with AASHTO R30. On game night, the oven is exclusively used for proficiency sample testing and the door stays shut for the entire duration. However, in a busy lab with technicians performing multiple tests, the same oven is often shared for other tasks.
As technicians open and close the door, the temperature stability may be affected, potentially influencing the final test results. This illustrates that the issue is not necessarily technical competency. Instead, it reveals how the design of a laboratory’s scheduling and operating system can influence the consistency of test results. In other words, the proficiency sample did not create this vulnerability; it exposed a vulnerability that existed within the laboratory’s existing workflow.
Three Places To Look For Root Cause
A low z-score is a valuable indicator that can reveal weaknesses within a lab’s processes. To uncover the source of the problem, a lab should conduct a thorough root cause analysis by examining three categories of potential causes.
- Technical causes include issues such as using out-of-calibration equipment or procedural errors.
- Operational causes include issues such as shared equipment, staffing issues, workflow issues, or scheduling conflicts.
- Human causes include issues such as training gaps, fatigue, or communication breakdowns.
Coach The System, Not The Player
When a root cause analysis uncovers an issue like a fluctuating oven temperature, a manager has a choice. Some managers might simply focus on the technician performance and issue a generic reminder to "follow the spec." Others may use the opportunity to examine whether there is an underlying issue that is contributing to the low rating.
A good coach does not simply criticize a player for missing a pass. They examine whether practice conditions, communication, positioning, or training methods contributed to the outcome and restructure practice sessions to create better habits. Similarly, an effective manager addresses the systemic bottlenecks. Perhaps designating a single, undisturbed oven exclusively for critical conditioning windows is the way to go.
The goal is not to assign or apportion blame, but to identify and remove obstacles that can make achieving consistent results easier. At the end of the day, both a coach and a laboratory manager share the same goal, which is to close the gap between daily practice and game night.
A proficiency sample should not become a special event to achieve a favorable z-score. Instead, it should provide insight into whether laboratory’s established processes can produce reliable and repeatable results. At the same time, daily testing shouldn’t be vulnerable to poor workflow and impossible deadlines that can influence test results.
Proficiency Testing as Game Day | Proficiency Testing as Daily Practice |
Assigned to the laboratory’s senior technician | Performed by any qualified technician(s) |
Daily workload removed | Integrated into normal workflow |
Maximum attention and resources provided | Routine procedures and equipment practices used |
Shows optimized performance | Shows typical system capability |
May hide operational weaknesses | Reveals opportunities for improvement |
A strong quality system doesn't expect technicians to suddenly elevate their performance just because the stakes are higher. Instead, it creates conditions that allow them to perform at that same high level every day. Just as great coaches build winning habits during practice, great laboratory managers build systems that make reliable performance routine – both during everyday testing and when the stadium lights come on.
