Why is VirtECS® Scheduler Unique?
VirtECS® - Virtually Exhaustive Combinatorial System
VirtECS Scheduler is powered by the VirtECS engine; APC's flagship technology and the core of all of its products. VirtECS enables the rapid development of an accurate and detailed virtual process that can be used as a surrogate for the real process to rapidly search many alternatives for process management and process analysis. The algorithm engineers at APC are leaders in the field of combinatorial optimization, the math underlying the proprietary VirtECS engine.
What Is a Virtual Process?
A VirtECS virtual process is a mathematical programming model that captures important process physics in the form of material balances, labor and equipment constraints, and other more general resource constraints. VirtECS is specially designed for batch, semi-continuous, and other processes that change state at discrete time intervals. The mathematical model underlying VirtECS uniquely handles the timeline in a way that permits as much detail as is needed, but in a way that is lightning fast. VirtECS algorithms can examine enormous numbers of timelines to focus attention on the best options for the real process.
Why Would Your Process Need VirtECS®?
Most scheduling systems on the market today are designed to work with discrete parts manufacturing. Processes that produce tennis shoes or engine blocks are inherently simpler to manage than chemical processes. Below we discuss several features of chemical/pharmaceutical manufacturing that are neglected by most scheduling systems on the market today.
VirtECS® Handles All of the Following Specialized Requirements
Limited Intermediate Storage
Partially machined cylinder heads may be stacked on pallets and set aside until needed. A batch of liquid intermediate must either be left in the vessel that produced it, or transfered into a suitable storage vessel to await further processing. Storage capacity for intermediates is frequently very limited and is often available only in vessels that are not dedicated to a single material. VirtECS specifically considers the details of intermediate material storage and always generates schedules that reflect the limitations imposed by these real world constraints. Virtually every other software system on the market today ignores these critical constraints, leading to schedules that cannot be executed in the actual process.
Limited Equipment Connectivity
While discrete parts may be transported manually from one part of the plant to another, chemical/pharmaceutical intermediates are usually piped. Thus, the scheduling system must explicitly account equipment connectivity. In cases where portable tanks are used, the system must know how many such tanks exist, what materials they can store, and how much time is required for cleaning between use.
Periodic Maintenance of Selected Equipment
A similar set of requirements is the need to shut down and recharge, or clean key equipment after a certain amount of time or workload has occurred since the last recharge. Ignoring constraints of this nature can result in seriously overestimating process capacity, premature initiation of upstream batches, and subsequent disposal of batches that cannot be processed due to equipment unavailability.
Minimum Run Length Constraints
Many chemical and biological processes have minimum run length constraints specifying that if a product run is initiated on a particular piece of equipment, the run must continue for some minimum time.
Clean-In-Place Requirements on Processing Equipment
Frequently, processes contain equipment that must be cleaned after each batch that is processes. Failure to account for the time and resources required to perform these tasks can lead to underestimated capacity and infeasible schedules.