Final answer:
The question refers to design constraints in an engineering context. Touching or crossing the line means a design component meets or exceeds the system's design criteria or specific design constraints. Without additional context, a precise definition of SDC or SCV cannot be provided.
Step-by-step explanation:
The question appears to be asking about 'SDC', which could refer to a System Design Criteria or Specific Design Constraint related to an engineering project. However, without additional context, it's difficult to provide a precise answer. Generally, in the context of system design, touching or crossing the line would refer to a component meeting or exceeding the predefined constraints or limitations established by the SDC.
For instance, if a design constraint specifies a size limit, a system component would need to fit within those dimensions to be compliant. Design constraints ensure that the system can operate effectively within the set parameters and are critical in maintaining the system's integrity, safety, and functionality. In the case of SCV design, which might involve criteria like safety, efficiency, or cost, components of the project must meet the outlined constraints to ensure the project's success.