This dataset relates to testing of a heuristic approach using operational research techniques for a specific routing problem in a warehouse, defined as the Storage Replenishment Routing Problem. There are a total of 620 instances, stored as .dat or .txt files, classified into two groups depending on the sizes of the instances. The 300 smaller instances consist of different settings ranging from 25 to 150 pick items and from 3 to 15 replenishment periods. Each setting consists of 10 instances randomly generated by changing the items to be picked in the warehouse, their locations in the warehouse, initial inventory levels, and maximum storage capacities in the forward storage area. The 320 larger instances involve 450 pick items and 15 replenishment periods, with each setting including 10 random instances generated by changing the items to be picked in the warehouse, their locations in the warehouse, initial inventory levels, maximum storage capacities in the forward storage area, and the skewness of the demand (ranging from uniform to 20-80 skewness). To use any of the instances, the user needs to read the data given in the corresponding text file into the optimisation software or the platform where their heuristic is coded in. The target audience for this dataset is operational researchers working on developing heuristic approaches for similar routing problems in warehouses.