Retailers must adapt their activity to comply with the evolving demands of their customers. Increasing demand on order-fulfilment services, along with determination to keep high service levels, have raised the problem of space scarcity at retailer stores to keep and process picked customer orders. Congestion is then experienced in store order-picking depots. A design proposition is given to overcome this problem for a top retailer’s store in the Netherlands. Using engineering design methodology, the design proposition is created with at least one short-term solution for each of the 3 stages of an item’s movements within the store: (1) incoming items; (2) storage and order-picking that includes storage at the sales SKU, job-sequencing, storage at the depot and storage during peak periods of activity; and (3) outgoing items. Long-term solutions are also given to look into that would enhance technology and prepare for the foreseeable future customer behaviour developments in purchasing methods. Empirical evidence is provided on different job-sequencing methods that extends order-picking theory on picker-to-parts systems; and further on causes for a more complex view of out-of-stock theory than from the perspective of a shopping customer at the store, instead focusing on out-of-stocks for paid items by an ordering customer.