## 1 Introduction  
In a fast-changing environment with increasing demand volatility, shorter product life cycles, new technologies, and new trade regulations, balancing supply capacity and market demand is a challenge for organizations all over the world. In this context, the capability of an organization to change as an adaptability characteristic is key in order to secure its viability. As a consequence, global managers are under increasing pressure to make decisions more quickly.  
While new technologies open new possibilities, many managers, even in well-established companies, do not have a system or virtual digital twin to enable them to foresee the expected outcomes of decisions that are to be made. Neither complete information nor all the implications of a decision are appropriately considered in most organizations. Because of this, many managers usually decide to start a process of collecting information to conduct an analysis as the basis for decision-making regarding capacity. This process involves different areas. Therefore, the decision is delayed until it has to be made, implying the loss of profit generation, as customers are not buying products due to a lack of capacity or long delivery times as a result.  
For all of these reasons, this paper attempts to provide an answer to those managers and their daily planning challenges by providing a conceptual model and a simulation of a case study. As a consequence, the practical relevance of this paper is a digital interface for decision-making support including technical, management, and economic key performance indicators. This interface provides a platform that can be used to avoid unnecessary investments, increase sales for all types of manufacturing companies, reduce operating costs, and support higher service levels. Moreover, the theoretical relevance of the paper is a novel approach that combines already consolidated scientific methods into a new concept for demand and capacity planning that is oriented to end-customer demand.  
The purpose of this paper is to develop a generic conceptual model for capacity planning in which decisions can be sped up in order to adapt them as quickly as possible to demands considering a level of risk for investments and changes in the production system. That is why economic parameters are considered to balance potential profit generation with investments or costs incurred. In this regard, the concept development presents different levels: network planning, location-related planning, and line planning within a location. With these three levels it can be taken into account whether it is a greenfield or brownfield scenario and whether it involves a new product launch.  
The main hypothesis is that a manufacturing company capable of adapting its capacity to demand using the structure of the viable system model (VSM) will be able to react faster and, therefore, applying this model will have a positive impact on the achievement of short-, medium-, and long-term goals of production companies. The VSM approach increases the adaptability of a company to face future potential scenarios, because the company will be able to make strategic decisions that will later influence the tactical and operative levels.  
Based on the conceptual model, a case study for an original equipment manufacturer (OEM) was chosen. It is a brownfield scenario in which there is a new product launch in a production line with two models using the same platform. By proving different scenarios and decisions to be made, the conceptual model is proven in order to check the hypothesis previously set.