Final answer:
The number of days prior to the conversion cycle that the MPS requests the pre-conversion roster can vary based on company protocols and industry standards; without further context, an exact number cannot be given.
Step-by-step explanation:
The Materiel Planning Schedule (MPS) is a crucial component in the conversion cycle for businesses, particularly those involved in manufacturing. To ensure a smooth transition, the MPS often requires that the pre-conversion roster be requested a specific number of days before the actual conversion takes place. However, without specific context or industry standards referenced in the question, it's challenging to provide an exact number of days as this can vary significantly by company, industry standards, or the specific processes in place at an organization. It is generally recommended to verify this information with the company's internal procedures or relevant guidelines specific to the industry or project.