CPIM Part 2, Module 6 - Detailed schedules Flashcards
What is the objective of scheduling?
Making the best use of manufacturing resources to meet delivery dates
A schedule in PAC exists out of five things, which five?
- The operations needed
- The sequence and routing of the operations
- The start and finish dates of each operation
- Time for each operation
- The work centers used in the operations
What is an operation set-back chart?
A graphical display of the bill of materials and lead-time information provided by the routing for each part
A variation of a gantt chart used in scheding is the control board, what is this?
A visual means of showing machine loading or project planning
There are two approaches to loading work centers schedules. Which two ways are these and what do they entail?
- Vertical: Each work center is scheduled independently. This approach keeps most work centers as fully loaded as possible
- Horizontal: Priority is on whole orders in order of overall priority. Does have lower capacity utilization.
What is de-expediting?
The reprioritizing of jobs to a lower level of activity. All extraordinary actions involving these jobs stop
What is block scheduling?
An operation scheduling technique where each operation is allowed a “block” of time
What is production activity control?
The function of routing and dispatching the work t be accomplished through the production facility and of performing supplier control
What is continuous process control?
The use of transducers (sensors) to monitor a process and make automatic changes in operations through the design of appropriate feedback control loops
What is a primary work center?
The work center where an operation on a manufactured part is normally scheduled to be performed
What are the four potential efficiencies to be gained from lot splitting and operation overlapping?
- Reduced total lead time
- Reduced work-in-process inventory
- Reduced floor space required
- Reduced size of transfer vehicles
What are the three potential downsides of operation overlapping / lot splitting?
- Increased cost of internal transport
- Disruption of work center schedule by expediting operations
- Lengthening of queue and lead time for other orders
What is the difference between a transfer batch and lot splitting?
A transfer batch is part of normal operations. Lot splitting is ad hoc
When is lot splitting not practical? (2)
- The setup time is high relative to run time
- A suitable work center or other additional capacity is not available
What is one less at a time?
A process of gradually reducing the lot size of the number of items in the manufacturing pipeline to expose, prioritize and eliminate waste
What is sequencing?
Determining the order in which a manufacturing facility is to process a number of different jobs in order to achieve certain objectives
What are priority rules?
The way in which orders are sequenced
What is order priority?
The scheduled due date to complete all the operations required for a specific order
What is dispatching?
The selecting and sequencing of available jobs to be run at individual work stations and the assignment of those jobs to workers
What are dispatching rules?
The logic used to assign priorities to jobs at a work center
Which type of scheduling is used for the critical operation and all subsequent operation? And which type is used for all operations before the critical operation?
- For the critical operation and all subsequent -> forward scheduling
- For the operations before the critical operation -> backward scheduling
What are the three ways that scheduling and PAC can be apporached?
- MRP - based
- TOC - based
- Lean - based
What is production reporting and status control?
A vehicle to provide feedback to the production schedule and allow for corrective action and maintenance of valid on-hand and on-order balances
What is the difference between batch and flow for PAC?
Batch processing systems need detailed feedback loops to keep queue and wait times reasonable. Flow systems only need flow control
What is flow control?
A specific production control system that is based primarily on setting production rates and feeding work into production to meet these planned rates, then monitoring and controlling production
What is input / output control?
A technique for capacity control where planned and actual inputs and planned and actual outputs of a work center are monitored
What is priority control?
The process of communicating start and completion dates to manufacturing departments in order to execute a plan
What are the four principles of job sequencing?
- Job sequencing rules determine order
- Sequencing commits one job at the time
- It loads jobs onto individual machines
- In a work center environment with variability, dispatching might not be able to determine next order untill prior job is done