Journal

Why the average closed-case time can hide the hardest cases

A single average can make a support queue look simpler than it is. Most cases may close quickly while a few remain unresolved for much longer. If the metric includes only closed cases, the longest open cases may be absent entirely. A careful analysis therefore separates completed-case duration from the age of open work and describes the distribution rather than treating one number as the whole experience.

The examples below are fictional and do not describe Corpay Prepaid, Fintwist, or any employer. NIST’s statistical handbook explains why different measures of location and distribution can tell different stories. This article applies those concepts to an illustrative payroll-support dataset. It is not a service-level commitment, a provider benchmark, or a forecast of how long an individual case will take.

Define the clock before measuring it State the start event and end event. Does the clock begin with the first employee contact, case creation, or completed verification? Does it stop when the team responds, when the underlying issue is corrected, or when the employee confirms resolution? These boundaries can differ substantially. A metric labeled “resolution time” is misleading if it actually measures the time to an initial response.

Also define calendar time versus working time, time zone, and any paused intervals. A business-hours measure requires a documented working calendar and pause rules. Do not subtract nights, weekends, or time waiting for another team unless the definition says so. If you exclude waiting time, provide a separate end-to-end measure when the employee’s experience depends on the full elapsed duration.

Compare mean and median on the same data Consider five fictional closed-case durations: 1, 1, 2, 3, and 13 days. Their sum is 20 days, so the arithmetic mean is 4 days. The median, the middle value after sorting, is 2 days. Both calculations are correct. The mean reflects the total duration spread across the five cases; the median describes the middle observation. Neither says that every case took two or four days.

The 13-day case is not automatically an error to remove. It may be the most important operational example. Investigate whether it reflects a valid complex case, a recording problem, or an unusual process interruption. Removing a legitimate long case simply because it makes the average worse would distort the measure. If a record is corrected or excluded, document the reason and show the effect where material.

Look beyond the middle A distribution view can show counts in duration bands, a range, and selected percentiles where the sample supports them. Define the percentile calculation method because different software conventions can differ, especially with small samples. A five-case dataset is too small for a stable story about the extreme tail. Do not present a highly precise percentile as though it were a dependable service promise.

Duration bands can be more readable for a small operational review: same day, one to two days, three to seven days, and more than seven days, for example. Those bands are illustrative choices, not recommended contractual targets. Choose boundaries that match the actual question and disclose them. If the team changes the bands later, avoid comparing the new chart directly with the old one without restating the data.

Keep open cases visible A case opened ten days ago and still unresolved has at least ten days of observed age. It does not have a completed resolution duration yet. Excluding it from the closed-case average may be necessary for that calculation, but excluding it from the report hides important work. Publish a separate open-case age view with the observation date clearly stated.

This is a form of incomplete observation: the final duration is not yet known. NIST discusses censored data in reliability analysis, but a simple operational report need not perform advanced survival analysis to acknowledge the issue. It can show the number open, their current ages, and the oldest unresolved case, while avoiding a claim that those ages are final resolution times.

Avoid a misleading period comparison Suppose one month closes many easy cases while complex cases remain open. Its closed-case median may fall even though the unresolved queue worsens. The next month may close the older cases and show a higher average despite meaningful progress. Compare closure metrics with backlog size, case-opening volume, and open-case aging before declaring improvement or deterioration.

A cohort view can help: follow cases opened during the same period and report how many remain unresolved at each review point. However, recent cohorts have had less time to mature. Label that limitation and do not compare a two-day-old cohort with one observed for a month as if they had equal follow-up. The choice of cohort and observation date is part of the result.

Explain what the measure can support A responsible summary might say, “Among the five closed cases, the median elapsed time was two days; two additional cases remained open at the review date.” That gives the reader a population and a limitation. It does not claim that the typical employee will receive a resolution in two days or that the provider guarantees that timing.

The most useful duration report keeps the clock definition, sample size, distribution, and unresolved work together. Averages are not inherently misleading, but they become misleading when their population is hidden. Use the fictional examples to check your reporting design, then validate the actual timestamps and definitions before drawing conclusions about any real payroll process.

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Sources and further reading

  1. NIST: Measures of Locationhttps://www.itl.nist.gov/div898/handbook/eda/section3/eda351.htm

    Mean, median, and the effect of distribution shape on measures of location; not a payroll service-level standard.

  2. NIST: Censoringhttps://www.itl.nist.gov/div898/handbook/apr/section1/apr131.htm

    Conceptual background on incomplete observation and censored data. Open-case ages here are reported descriptively, without survival estimates.

  3. Corpay Prepaid: Fintwist is now Corpay Prepaidhttps://www.corpayprepaid.com/

    Current provider naming and the distinction between PayCard wages and other prepaid disbursement products; not evidence of this publication’s affiliation or any employer’s program.