Blog · Data quality and reconciliation
How a single large order distorts every measure built on it, the norm it inflates, the run rate it doubles, the concentration it spikes, the share of wallet above 100 percent it produces, how outliers are detected from the account's own history and the segment's distribution, the rule that they are flagged and shown rather than removed, the medians that make norms robust to them, and the two kinds of outlier that are not errors at all.
A mid-sized account places one order for a plant opening, ten times its usual size. The next month its share of wallet reads 180 percent, its run rate has doubled, its segment's norm has risen, and it is the company's fourth-largest customer. Every one of those is arithmetic on a real order and every one misleads. This guide sets out what an outlier does, how it is detected, the flag-and-show rule, and the two kinds that are not errors.
| Measure | Effect |
|---|---|
| Run rate, three-month window | Doubles; annualised figure is fantasy |
| Share of wallet | Above 100 percent; the wallet estimate looks wrong |
| Concentration | The account jumps into the top ten for a quarter |
| Norm, if computed as a mean | Rises for every similar account; every gap widens |
| Dormancy, next year | The account's cadence and typical size are distorted |
| Forecast bias | The rep who forecast it was right once and wrong on the trend |
Two tests per order, stated:
Own-history test: order value > k × the account's median order, trailing year, with at least n orders Segment test: order value > the stated percentile of the segment's order distribution
Either flags. The flag carries the reason.
| Where the order appears | Treatment |
|---|---|
| Ledger and identity | Included; the identity holds |
| Concentration | Included, flagged on the account |
| Run rate | Shown with and without; the without is the default for ranking |
| Share of wallet | Shown with and without; the wallet estimate is not revised on one order |
| Norm | Unaffected: norms are medians |
| Forecast | Excluded from the trend; included in the actual |
A norm computed as a mean moves with one order. A median does not. Every norm on this site is a median or a percentile for that reason, and a mean is used only where the report says so and why.
| Kind | Looks like | Treatment |
|---|---|---|
| Project or opening order | One order, one product family, then back to cadence | One-off flag; excluded from run rate; kept in the ledger |
| Step change | A large order, then a new higher cadence that holds | Not an outlier after two more periods; the account moved band |
The second is the customer growing, and the report re-reads it as a step change once the new level repeats.
| Account | Median order | This order | Multiple | Segment percentile | Flag | Reason logged |
|---|---|---|---|---|---|---|
| 4471 | $9,000 | $92,000 | 10.2 | 99.8th | Yes | Plant opening, per rep |
| 2207 | $40,000 | $58,000 | 1.5 | 91st | No |
| Account 4471 | With order | Without |
|---|---|---|
| Run rate, annualised | $410,000 | $112,000 |
| Share of wallet | 180% | 49% |
| Rank by revenue | 4 | 38 |
The reader sees both, and the reason.
Removed. The identity breaks and a real order vanishes.
Not flagged. Share of wallet at 180 percent; the wallet method blamed.
Norms as means. One order moves every similar account's gap.
Step change flagged forever. The customer grew and is treated as an anomaly for a year.
Mapped once, the ledger's history produces the two tests, the flags with reasons, and every affected measure with and without the flagged orders. Covirage builds this from the exports as they are. The metrics governance solution describes the setup, and the run rate guide covers the one-off order as one of the four ways run rate misleads.
Because the order happened, the revenue is real and the ledger has it. Removing it breaks the identity and hides a fact. Flagging it and showing the measure both ways keeps the identity and gives the reader the choice, with the reason on the line.
Two tests, stated: the order is beyond a multiple, say five, of the account's own median order over the trailing year; and it is beyond a percentile of the segment's order distribution. Either flags it. An account with fewer than a stated number of orders uses the segment test only.
A project order, a customer building stock ahead of a price change, a new site's opening order. They are real, they will not repeat, and the report treats them as one-off: excluded from the run rate window with a note, kept in the ledger and the concentration figure, and flagged on the account for the next period's comparison.