Keywords: Inventory optimization; KPIs; Performance management
Inventory management can be perceived as a big part of logistics operations for distributor companies.
Decisions made in terms of stock levels, storage area, and order quantity have a significant impact not only on inventory costs and risk of being out of stock (OOS), but also on timely replenishment operations, shelf availability and even relationships with customers.
Most of the senior managers spend extensive time and effort through the review of elongated and detailed reports for making decisions accordingly.
To cover broad, organizational, and functional aims of inventory management and to make rapid decisions in today’s fast-acting environment, we need smart, time-saving, easy to interpret and most importantly decision-supporting key performance indicators (KPIs). In this regard, I would recommend five smart KPIs for optimal inventory management.
1. Inventory Turnover Ratio (ITR):
ITR: COGs / [(Opening Stock+Closing Stock)/2]
2. Turn-Earn Index (TEI):
TEI: (ITR) x (Gross Profit %) x 100
3. Gross Margin Return on Investment (GMROI):
GMROI: [Gross Profit] / [(Opening Stock+Closing Stock) / 2] X 100
4. Days of Supply (DOS):
DOS: Average Inventory / Monthly Demand x 30
5. Inventory Velocity (IV):
IV: Next Month's Sales Forecast / Opening Stock
Benchmark: For continuous SKUs, keeping IV between 60-70% will provide a good match of demand while 75-80% of IV can be more beneficial for fast-moving SKUs. Whilst having IV less than 60% indicates excessive stock, IV over 80% is risky in terms of being out of stock as it calls for Kanban-Pull system.
Practically, not all SKUs or brands can be treated equally via aforementioned KPIs. Applying Pareto Principle will help easily categorize SKUs (e.g. fast-, continuous-, intermittent- and slow-moving SKUs). Categorization can be based on monthly sales volume, margin percentage or the number of exits from the warehouse. Making use of Pareto Principle upon these three perspectives and then taking the average weights will be a good asset in terms of placing each SKU to the correct category.

