In the context of rotational moulding (RM), linear medium density polyethylene (LMDPE) is by far the most popular thermoplastic for load-bearing parts (e.g. underground water tanks), primarily because of its wide processing window, ideal melt flow properties, low cost and excellent toughness. On the other hand, the stiffness of LMDPE is relatively low in comparison to alternative polymers such as polypropylene; this low stiffness warrants the application of finite element analysis (FEA) on load-bearing RM designs to validate their structural integrity before production. An exploration of applying FEA in the design of rotamoulded parts is presented.