Holcim Ltd. is trying to reduce costs for their raw material extraction mobile fleet, especially for hauling, loading, and haulage support. To achieve this, the fleet hast to be optimised and the efficiency has to be raised. For this, Holcim Technology Ltd. (supporting organisation) introduced a "Site Assessment" strategy to find potential improvements at their sites regarding the mobile fleet. According to this assessment an estimated annual savings of about 35 million USD worldwide in loading and hauling should be realised. The Regional Support Organisation Europe of Holcim Ltd. currently invests too much time for implementing these "Site Assessments", which require up to four weeks. Therefore, an own “Light Site Assessment” for their mobile fleet, which takes only one to three days, should be developed. The goal of this present work was to create this kind of assessment method and a guideline, which would help the assessor to find the most necessary improvements. Starting point is the original "Site Assessment" strategy and assessment methods found in the literature. In order to quickly fulfil the aim of assessing a site, not all criteria can be taken into account. For finding the most important criteria, a Pareto analysis is executed. In the end, an expert should easily find the critical points regarding the mobile fleet with the “Light Site Assessment” guideline. For evaluating the method, two pilot projects are executed. The resulting method makes it possible to show considerable improvements within approximately three days, but it is not pointing out the way of solving the problems. The whole procedure of the “Light Site Assessment” is based on a qualitative and quantitative assessment. In practice, all criteria are scored throughout the assessment process (quantitative). Therefore, summarising the score of all criteria in a category shows a final statement of this category (e.g. field of work). All different category values can be seen as key performance indicators of the machines and of the site itself. Comments (qualitative) about each assessed criterion help the assessor in stating a final proposal regarding the mobile fleet improvements.