Which manufacturing concept is characterized by all costs being variable, often referred to in fixed position settings?

The correct choice highlights the manufacturing concept known as "Project." This approach is often associated with fixed position settings where a unique, complex product is produced. In project management and manufacturing, the term "project" typically refers to scenarios where all costs are variable due to the unique requirements and specifications of each endeavor. This means that while there may be fixed costs associated with the initial setup, various elements such as materials, labor, and overhead can fluctuate based on the specific demands of the project.

In fixed position settings, where the product (like a large construction project or shipbuilding) remains stationary, all resources and costs are directed towards the completion of that singular effort, reinforcing the notion that all costs are variable in relation to the project's scope and changes. This flexibility in resource allocation is critical in ensuring that each project can adapt to specific customer requirements or unforeseen challenges.

Other options represent different manufacturing concepts that do not align with the idea of all costs being variable in a fixed setting, such as job shops focusing on small-batch custom production, economies of scope that leverage existing resources for multiple products, or flexible manufacturing systems designed to handle multiple products with some level of standardization.