To assess whether a warehouse is suitable for inventory sampling, it is irrelevant whether deviations are positive or negative. All deviations are included in the sampling error calculation as absolute values. As a general rule of thumb, deviations below 10% of an item’s value tend to have only minor negative effects on the result, whereas significant deviations (≥ 100%) can heavily influence the outcome even if they occur infrequently.
A helpful indicator is the daily number of inventory error corrections, which can provide insight into the quality of inventory records. Another useful reference is the result of the most recent full physical inventory: if only minor discrepancies were found and the total valuation difference was low compared to the cost of the full count, this may support the suitability of inventory sampling.
Additionally, a recent full count allows for inventory sampling simulations. Since each base unit position has both book and actual inventory values, it is possible to run a large number of simulated inventory samplings (≥ 100), providing a basis to evaluate whether actual implementation is advisable.
A test inventory sampling can also serve as a preliminary measure to assess inventory reliability. It can identify problematic areas and help improve parameters before the actual sampling inventory is carried out. Even if full implementation is not yet feasible, a test run can be helpful for adjusting the calculation model and gaining practical experience with the method.