A pre-shift alcohol check does not run well just because you set a time to open the testing station. At manufacturing and construction sites, workers enter, change into work clothes, and move to their work area. In transport and aviation, the check is followed by dispatch or crew preparation. Here, an alcohol check is the operating process in which each arriving worker completes the test procedure and the result confirms whether that person can be assigned to the planned task.
The key is not to decide by habit how far ahead of the shift start the check should be. Instead, work backward from the time the last arriving worker can actually start work. If you break the flow into waiting, identity confirmation, re-check, travel, and work preparation, you can tell whether the problem is too little testing time or a poor route, and the right action differs for each.
Fix the work start time first
The end point of the schedule must be more specific than "shift start." For example, at a worksite, define it as the time workers arrive at the work zone and receive their assignment briefing. In transport operations, define it as the time driving or crew preparation begins. If this reference is unclear, some people will finish the check but still arrive late at the work area, and it becomes hard to tell which step caused the delay.
Next, list the actions needed before work starts, in reverse order. If you lay them out as putting on work clothes, collecting protective equipment, moving to the work area, confirming the test result, and joining the testing queue, the question is no longer how many minutes earlier the check should start. Instead, you see which segment has no slack. Also mark conditions that cluster at specific times, such as shuttle bus arrivals, shift handover crowds, and access badge checks.
Observe the test process and the travel after it separately
Check time does not mean only the time spent standing in front of the breathalyzer. Look at when testing ends, including worker identification, waiting, result confirmation, and separate guidance when a re-check is needed. A re-check is a process in which the first result is not finalized right away but is checked again under a set procedure. It is important to separate routes so that people in a re-check do not block the general queue.
Measure the time after testing separately as well. If the testing station is at the main gate and the work preparation room or assignment area is far away, delays remain even if the queue gets shorter. On the other hand, if travel time is short but the queue is long, it makes more sense to adjust the check-in start time, staff assignment, and flow at the testing location. This is why you need to find where the delay occurs before moving the check earlier across the board.
How to turn observations into a schedule
As a hypothetical example, consider a worksite where workers take an alcohol check at the main gate before the morning shift, pass through a work preparation room, and then move to the work zone. Observation shows that most workers finish testing within the set time, but a queue forms right after the shuttle bus arrives. The last workers are late for the assignment briefing because of the time it takes to go from testing to the preparation room and then to the work zone. In this case, the delay is caused not by testing itself but by the period when people arrive all at once and the travel segment after testing.
Two possible actions can be considered. One is to align check-in start times with bus arrivals to reduce crowding. The other is to adjust the testing location and the work preparation route. The location and staff for handling people who need a re-check should also be kept separate from the flow of people who have finished normally. The completion standard is not that the first arrivals pass quickly. It is that the last arriving worker also finishes the check, preparation, and travel and reaches the set work start time.
| Time segment | What to observe at the site | Decision to reflect in the schedule |
|---|---|---|
| Around check-in | Times when shuttle buses and individual arrivals cluster | Check-in start time and notice time |
| During testing | Queue, identity confirmation, and the flow that branches off to re-check | Staff assignment and re-check route |
| After testing | Changing into work clothes, collecting protective equipment, moving to the work area | Time to leave for check closing and work preparation |
| Just before work starts | People late for the assignment briefing and those who have not finished | Separate contact route and follow-up timing |
Rather than filling each segment in the table with a single average, it is better to record the actual reasons for delays. Include conditions that change the flow, such as days when rain slows travel, days when shift crews overlap, and days with irregular arrivals. That way, you avoid a schedule that looks right most of the time but delays work start on certain days.
Do not leave re-checks and unfinished workers for the end
In addition to check-in and end times for regular checks, the schedule should set a cutoff time by which the re-check procedure can start. If you do not decide in advance who confirms the result when someone needs a re-check, and who communicates whether that person can be assigned to work, the site supervisor ends up making the call just before work begins. What needs to be communicated here is not an abstract "status" but whether that worker has completed the check and whether they will be assigned to their planned task.
Put the route for people who arrive late without completing the check in the same document. For example, if some workers may arrive when the regular check staff is not on duty, write down separately who will be contacted, who will take over the check procedure, and who will adjust the assignment roster. With this in place, the site can reduce cases where workers are put to work arbitrarily or, conversely, are kept waiting while staff look for someone to handle them.
After launch, look at delay points rather than late headcount
After a pilot run, do not evaluate the schedule only by the number of late workers. Compare which segment ran past its planned time: from arrival at check-in to test completion, from test completion to the end of preparation, and from the end of preparation to work start. Looking at the waiting time of the first arrivals together with the work start delay of the last arrivals also shows whether moving the check earlier actually worked.
It is better not to finalize a plan that requires earlier arrival for the check based only on site convenience. Because it can affect working conditions such as working hours and wage processing, the relevant departments must review it and operating standards must be organized first. A risk assessment is the process of identifying hazards and risk factors, including work behavior, and setting up and carrying out improvement measures to reduce risk. Congestion and delays found in the pre-shift check route can therefore also be reviewed as operational improvement tasks to reduce worksite risk.
In the final schedule, record check-in start, regular check end, re-check cutoff, work start reference, and the contact order for late arrivals on the same basis. If these times differ across the arrival notice, the check staff roster, and the site assignment plan, bottlenecks will reappear in actual operation. Even after a schedule is set, keeping a record of which segments you adjusted based on observation gives you a basis for decisions when applying it to the next shift or another work zone.
