The Lean improvement method distinguishes eight categories of waste. One of these is ‘stock’. Too much stock is not good, but neither is too little. Having stock also provides a safe feeling of availability in times of uncertain internal planning and external factors that cannot be directly influenced. Because optimising availability in your own company and in the supply chain is often not the core competence of our customers, itsme can take over the care of this optimisation, for example via the entry and management of so-called Vendor Managed Inventory systems. But how do you know whether VMI is indeed the right solution? Ralph van Aartsen can answer that crucial question – based on five questions. Here are his answers to our questions about VMI.