Planning and Scheduling

Case Studies

CASE #1: Locomotive production planning with AutoSched

How can we generate and analyze various planning scenarios in 30 minutes, when generating a single scenario required us an entire week of effort ?

Situation:

To build locomotives, from the planning and scheduling point of view, looks very much like building planes: each order is a unique project even though it is for a known model. Indeed, all the customers have their own special requirements. Before AutoSched, generating a 3 month production plan for the main assembly lines and the production centers was requiring one full week of work for the two planners. Now, with AutoSched, the same activity is done within 5 minutes! While it was impossible for them to test different scenarios (i.e. the first plan had to be the good one) with their original method, the two planners can now concentrate on analyzing and fine-tuning their plans. In the same way, they have now the flexibility to regenerate this plan and test scenarios more often and faster, to take into account for example changes in the orders or production problems. Even though these two benefits are merely intangibles, the competitive advantage they give to the company is obvious.

Solution:

How did this all happen? After a week of formal training on AutoSched, provided on-site by MultiCIM, and a few weeks of practice, the planners began to create the model of their facility, focusing first on the main production and assembly line. Using manual data entry or by importing the information into the spreadsheet interface of AutoSched, they were able to create the basic simulation model within a couple of days. This model included the definition of the work centers, a list of models, their main sub-assemblies and their respective routing and BOM. In close collaboration with MultiCIM's consultants, this model was then refined to take into account their unique production constraints and objectives, as well as the Theory Of Constraints (TOC) approach they were using for scheduling the assembly and supply lines. Special decision rules were developed to mimic the way this scheduling had to be done. Finally, custom decision reports (for uploading into the MRP system, the management, and the shop floor ) were designed in AutoSched to provide the company with the same type and format of information they were using before AutoSched. These reports are now automatically generated by AutoSched.

This took a cumulative total of 10 weeks of work, during which the model was implemented, tested and validated against different samples of data.

CASE #2: Coordination of equipment and forge simulation with AutoSched

How can we achieve a higher productivity and synchronize our forges and furnaces given our numerous production constraints?

Situation:

The rotary forge department of this US company has just doubled its production capacity by adding a new forge. These two machines are surrounded by auxiliary equipment (furnaces, saws, cooling baths, conveyors, etc.) and all of these activities have to be well coordinated to minimize the cost and keep a high level of plant productivity. A large amount of constraints have to be considered in order to achieve this objective. Already difficult with a single machine, this task was becoming impossible to handle without the help of a finite capacity scheduling package. After unsuccessfully trying a Artificial Intelligence-based package, the company turned to AutoSched and MultiCIM to implement a viable solution.

Problem:

How can we take into account the wide spectrum of constraints (hammers' limited capacity, heating/cooling of furnaces, limited quantity of hot boxes for special material, etc.) and optimize the resources' utilization while keeping the production costs as low as possible?

Solution:

MultiCIM was hired to develop an AutoSched model of the rotary forge department that would take into account all the production constraints. This model was to be integrated with the new Manufacturing Execution System (MES) from which it would retrieve the information regarding the orders on their way to the rotary forge and the current WIP. The development focused on the ease-of-use and accuracy of the model. In order to simplify its daily use and maintenance, the number of routings was kept to a minimum while the manufacturing information was passed together with the order information received form the MES. The unique loading scheme of the furnaces has been reproduced in the model and customized decision rules were developed for each piece of equipment. These rules were built by MultiCIM's consultants after conducting a series of interviews with the shop engineering and scheduling team. The flexibility of AutoSched allowed us to fine-tune and improve these rules while testing the model under various production scenarios. These decision rules are capable of dynamically balancing account local constraints (e.g. current hammer set, current capacity available, etc.) together with global information (e.g. quantity of pieces still remaining to be forged on the current hammer set, contents and temperature requirements of the material in support furnaces, etc.).

According to the company, the model, which is now used daily since 1995, allowed them to generate better schedules faster than the expert human scheduler would have been able to do.