Cycle time has a direct influence on number of returnable crates needed and therefore a crucial parameter for cost structure and pricing of the user fec in the pool system.For providing the growing market, number of crates has to increase as well as the utilization of existing crates. To accomplish this aim, cycle time for the whole supply chain has to be fully unravelled and understand.The purpose is to map cycle time and stock movements, to see how, where and when crates are being used in the supply chain. The goal is to make a method of cycle time calculation, together with suggestions of improving the pool system and decrease cycle time.The study has been a combination of qualitative and quantitative research and comprises the three biggest wholesalers in Sweden; ICA, Coop and Axfood. Furthermore have 65 grocery shops, connected to the wholesalers, been investigated and mapped.The study has come to a conclusion that cycle time for an average returnable crate is 19 days. The full-size and half-size crates have a bit longer cycle time, 21-22 days, while Dual Height-crates and shallow haif-size crates have 17-18 days.