Skanska is using work schedules that are specifically designed for employees in the production. These work schedules are called best practice. These are guides containing technical descriptions, design references, capabilities, etc. for work activities. This support function facilitates the work preparation and planning of future work. For placing unbound base course, there are only few capacities specified in the best practice model. The possibility of correcting the capacities is considered to be minimal. Hence, Skanska has requested to supplement the best practice with correction values based on factors that affect it negatively. With the correction values capacities can be used for similar projects.  The purpose of the report is to assess an approach taken to produce correction values. A general process model was used to produce correction values. The model follows four steps to generate correction values ​​using reported production data. By collecting data, categorize and process the data, correction value can then be calculated. The model's second step categorizes the production data by similar factors. An average correction value can then be calculated for every category. During the study, it has been clear that the production data must contain the right information to allow categorization of data. In order to verify and ensure the right information is provided, own follow-up forms can be designed. The focus of the follow-up forms is to answer questions that enable a categorization. The study examined road-width and settlements as influencing factor in placing unbound base course.