Objective Although the quality of long‐term care has improved, many problems still remain, and better processes seem to be necessary. Hence, outcome‐oriented management is of particular importance. The Resident Assessment Instrument (RAI) is a tool that has been used successfully in many countries to improve quality of care. However, there are problems of implementation and it lacks information on the conditions of successful or failing information of the RAI. The aim of this article is to find out to what extent technical/qualification requirements help to introduce or lead to failure of the implementation of an assessment instrument like RAI. Methods Therefore, a cluster randomized controlled trial showed services using RAI intensively tend to have better outcomes after 12 months. But the effects depend on the success of the implementation. Using a factor analysis, an index was built to divide the care providers into “optimal” and “suboptimal” RAI users. Results Some factors that seem to lead to a rather successful implementation could be detected: A higher proportion of qualified staff, a lower perceived quantitative workload, a small size of care providers, the type of ownership (for‐profit) and a late entry in study [Correction made here after initial online publication.]. Conclusion The success or failure of the implementation of an outcome‐oriented control instrument is determined by professional, organizational restrictions. The results show that a better implementation leads to better outcomes for clients. Copyright © 2013 John Wiley & Sons, Ltd.