Amanda Aldridge, head of retail at consultancy KPMG, has worked with Sainsbury's and Waitrose. She says: "Within a retail environment, supply chain is absolutely critical. The supply chain is where retailers have been looking to drive out cost savings, but this is pretty dire if it means 'stock outs'. Having plenty of product at one end of the chain but none of it where it matters - on the shelves - can make or break a company.