Standard Work is a very useful tool of the Lean Production paradigm to specify standards and to establish the best methods and sequences for each process and for each worker, helping to reduce wastes. Despite its usefulness, this tool is often underused, neglected and misunderstood. Apart from that, there is a lack of literature about Standard Work. It is possible to find many papers on Lean Production in general and on some Lean tools, but there are few that focus on or describe in detail this particular tool. The main purpose of this paper is to prove the validity and show the importance and the applicability of Standard Work. The main aspects and ideas to understand this tool are described, as well as the benefits of applying it in a real world manufacturing environment. In this paper, an application example is given on a production unit of an elevators company, following the Action-Research methodology. The main findings are that Standard Work is effectively a good tool to normalize work procedures, allowing increased flexibility and production, and decreased wastes and assembly errors.