The paper focuses on refining a Workload Control (WLC) concept to improve the applicability of the approach to the shop characteristics found in practice. This is a two-stage process leading to significant conceptual refinements to a key WLC methodology. The first stage focuses on the development of a Decision Support System (DSS) based on a WLC concept designed for Make-To-Order (MTO) companies. Refinements made include changes to the backwards scheduling procedure and the way in which jobs are released onto the shop floor. The second stage focuses on the process of implementation. Using a case study of a MTO company, the paper describes the strategy taken to overcome a number of prerequisites to the successful implementation of a Production Planning and Control (PPC) concept. Issues addressed include grouping machines and determining capacities. This case study adds to the available literature by looking specifically at implementing WLC from the customer enquiry stage, while the case study experience also provides further refinements to the WLC concept.