Much research regarding efficiency in manufacturing industry has historically been focused on the material activities of the shop floor. However, companies that merely focus on material activities when trying to improve lead times, risk losing potential for improvements within immaterial activities such as planning, engineering, design, and purchasing, which often constitute the most time consuming parts of the order fulfillment processes. Engineer to order (ETO) products are particularly time consuming regarding their immaterial activities, and the customer is waiting for the products from the very beginning of the order fulfillment process. Shortening the lead time to customer for ETO products is therefore important for customer satisfaction. The aim of this study is to adapt an existing lead time tree model currently focused on material activities to also include immaterial activities, enabling a full visualization of all activities contained in order fulfillment processes. The lead time tree model would thereby be able to use as a tool when working on shortening the lead time to customer. A further aim of the study is to investigate how the adapted lead time tree model can be used in further areas as well, in addition to visualizing immaterial activities. The adaption of the lead time tree model has been based on the original literary source of the lead time tree model. The original lead time tree model has been analyzed towards theoretical data from a literature study, and towards empirical data about immaterial activities in order fulfillment processes for ETO products, from the case company Kongsberg Maritime Sweden AB (previously Rolls-Royce AB). The result of this has been an adapted lead time tree model that can visualize immaterial activities. Several adaptions of the original lead time tree model have been made for it to be able to visualize immaterial activities, while still keeping the basics of the original model. The adapted lead time tree model comprises information that is normally kept separated and that is important when planning and improving a process. Additional information that is needed for each specific case can also easily be included in the lead time tree. The adapted lead time tree model has proven to have additional areas of use within project planning, improvement work regarding lead time reduction and root-cause analysis, and as a boundary object for communication between internal actors and between internal and external actors. The adapted lead time tree model is presumably able to map and visualize immaterial activities in other fields of business as well, other than manufacturing, as the nature of immaterial activities remains the same across business environments.