Which one of the following statements about the Value Stream Mapping (VSM) is TRUE?

a. Often in value stream mapping, analysts must rely on process information from shop floor workers rather than direct observation in an effort to quickly develop a work plan and accelerate implementing the improved process.

b. The theory of constraints accepts existing system bottlenecks and works to maximize throughput given these constraints, while value stream mapping endeavors to understand how existing processes can be altered to eliminate bottlenecks and other wasteful activities.

c. A value stream map shows the flows of materials and information and the lines of responsibility and authority.

d. The value stream mapping tool often requires completion of the future state drawing before the current state drawing, to help managers see the future state goals and more easily identify problems with the current state of the process.