Optisol is a software company located in Texas. By providing powerful scheduling software it has been helping job shops manage their complex production efficiently. There are numerous small and mid-sized manufacturing industries which are engaged in order-driven, high-variety production in which distinct products (of different routings) may simultaneously flow through the system competing for many shared resources in order to meet respective due dates. One of the difficult problems faced by them is how to determine a rational due date (or production lead time) and a right material release time for a new order based on process & resource requirements of the order and on the existing workload and resource capacities. Another difficult problem is how to manage rush orders and order priority changes without drastically delaying deliveries for customers. To make distinct types of products against customer orders, they employ multi-skilled workers and multi-functional machines. To squeeze more productivity from machines, they may even run more than one shift. However, they find it very difficult to schedule order-driven, high-variety production subject to resource constraints for maximizing throughput and on-time delivery and minimizing work in process and production lead times of orders. Optisol provides most powerful scheduling software to help such industries schedule production optimally.