Detailed Scheduling and Planning (MRP & Capacity) Flashcards

What is 'safety time' in MRP, and how does it differ from safety stock?

Answer: Safety time adds extra lead time offset; safety stock adds extra inventory quantity

Safety time offsets the planned receipt date earlier than needed (adding lead time buffer), while safety stock adds a quantity buffer to protect against demand variability.

Which lot-sizing rule minimizes total of ordering and carrying costs by evaluating period-by-period combinations?

Answer: Part period balancing

Part period balancing combines periods until accumulated carrying cost approximates the ordering cost, balancing the two types of costs.

In manufacturing, 'routing' provides which key information for planning?

Answer: The sequence of operations, work centers, and time standards for producing an item

A routing defines each operation in the production process, the work center where it is performed, and the setup and run time standards used for scheduling and capacity planning.

What is 'queue time' in a manufacturing routing?

Answer: Time a job waits in front of a work center before processing begins

Queue time is the waiting time a job experiences in front of a work center and is often the largest component of manufacturing lead time.

Which scheduling method assigns jobs to work centers by starting from the due date and working backward?

Answer: Backward scheduling

Backward scheduling starts from the required completion date and subtracts lead times to calculate the latest start dates for each operation.

What is the purpose of 'firm planned orders' in MRP?

Answer: To fix a planned order so MRP will not automatically change its date or quantity

A firm planned order is manually frozen by the planner to prevent MRP's automatic rescheduling logic from changing it, useful when the planner has knowledge MRP lacks.