April 25, 2018 at 3:34 pm #3572Honghan YeParticipant
I want to know how the production manager schedules their job orders. Do they follow some simple sequencing rules? Like first come first serve. Is there any real application for those meta-heuristics to optimize the job schedule?April 26, 2018 at 10:19 pm #3597Richard OhrtParticipant
There are a number of methods used. Sometimes there are launch rules for mixed model lines to prevent high content models from blocking the line. Sometimes the model mix is driven more by parts availability than by the ideal situation, however.
I have seen units use a dynamic simulation modeling package that will actually predict the best model mix lineup based on the work content compared to the production needs.April 27, 2018 at 10:13 am #3606Stefan CloerenParticipant
For my organization I am interested in tbis post. I would like to see how data analytic techniques are incorporayed into scheduling.April 27, 2018 at 11:59 am #3607Mohammed AliParticipant
Generally speaking, there are two approaches for managing and planning material. One is quantity based and the techniques used are reorder points and the two-bin system. The other is time based and uses material requirements planning (MRP).
Reorder points are determined by calculating the average demand during the replenishment lead time, plus safety stock. The resulting figure is compared against available daily inventory, which is the sum of stock-on-hand plus existing schedules. Whenever the reorder point is equal to or greater than the available inventory, a message to replenish is generated. Two-bin system and reorder points operate similarly, the two-bin system does not require daily inventory transactions to be recorded. Rather, it separates inventory into two locations, and whenever one becomes empty, it triggers a reorder for more material. The second bin must contain adequate inventory to satisfy the average demand during the replenishment lead time, plus safety stock.
Material requirements planning is a set of procedures, decision rules, and policies that govern many of the routine decisions required in setting the manufacturing schedule. As such, it provides a highly disciplined approach for arranging lower level factory schedules. MRP depends on shop events happening just as they were simulated by the computer. The simulation is based on the plans entered in the master productionMay 2, 2018 at 12:12 pm #3697Hang MaParticipant
Heuristics are the commonly used ways in practice like you mentioned. Usually I think it depends on what objectives the manager is focusing on. For example, with respect to a facility manager, to meet the due date is his primary purpose, then EDD or minimizing tardiness the the main goal. For job shop manager, sometimes, namely scheduler, their main goal is to assign jobs to properly to make the utilization largest, thus minimizing Cmax or minimizing flow time maybe the best choice.
The key is how to construct the appropriate heuristics. A type of machine learning method, such as Genetic Programming, utilizes hyper heuristics to train useful heuristics using the history data which maybe a new direction for practical implementation.May 22, 2019 at 7:40 am #4971Maria GarciaParticipant
Great Information you have shared .Really very helpful to all .
You must be logged in to reply to this topic.