Final answer:
option c,The best rough-cut capacity planning tool for a factory with complex and variable production requirements is capacity planning using overall factors.
Step-by-step explanation:
For a factory that deals with long lead times, multiple products, different time requirements per product, and a variable product mix week to week, capacity planning using overall factors (C) works best. This rough-cut capacity planning tool is suitable for situations where the product mix is complex and changes frequently. It allows factories to estimate the overall capacity needed by applying overall factors, such as average setup time and average run rate, across all products to determine if sufficient capacity is available for the entire system.
Capacity planning using overall factors takes into account the varying mix and time requirements by considering a mix of products that a factory might produce and assigning a weighted factor to each based on historical data or estimations. This method helps to simplify capacity planning when dealing with numerous products and is more adaptable for environments with high variability.
While the other options like capacity bills, resource profiles, and the notion of 'none of these are correct' may be used in different contexts, they are less effective for the scenario described due to the complexity and variability of the production process.