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Table 1 Overview of the main spare parts classification researches

From: Teleconsultation demand classification and service analysis

References Classification criteria Cut-of values of criteria Classification results Assumption
[14] The mean number of lead times between demands 0.5, 0.7, 2.8 Three categories: sporadic, slow-moving, smooth Poisson demand arrivals
The ‘lumpiness’ of the demand
[15] The ratio of average inter-order interval and forecast review periods 1.25 Poisson demand arrivals
[16] Transaction variability 0.1, 0.53, 0.74 Five categories: smooth, irregular, slow-moving, erratic, highly erratic
Demand size variability
Lead-time variability
[13] The square coefficient of variation of demand sizes, The average inter-demand interval 0.49, 1.32 Four categories: erratic, lumpy, smooth, slow Bernoulli demand arrivals
[12] The number of zeroes in the last 13 periods 5–8 for Croston method Intermittent
2–4 for the SBA method Non-intermittent
[17] Frequency Pareto classification (80%, 95%, 100%) Three categories: A, B, C
Demand value
[18] The item first occurred; The average quarterly demand; The average time between demands (quarter); Standard deviation to mean ratio 3, 8; 25; 2; 1.75, 2.50 Lumpy Outliers must be removed
Erratic
Limited demand
[8] Correlation; The coefficient of variation in demand volume; The proportion of periods with zero demand; Mean demand volume