Finite Capacity Scheduling Software Overview

Finite Capacity Scheduling (FCS) is a method of scheduling that considers the real world capacity constraints of your organization.  These capacity constraints typically include your operation’s machines, tools, labor and material.

The biggest single benefit of Finite Capacity Scheduling is visibility.  FCS accurately predicts operation start and finish times, as well as order, or requirement, start and finish times.   This visibility into the future allows you to best manage the trade-offs involved in running your plant efficiently, while still satisfying your customers.

As alternatives to Finite Capacity Scheduling, you might be using the infinite planning capability of your ERP / MRP system, or you may be using wall boards, spreadsheets, or project management tools.  Infinite scheduling approaches typically backward scheduling using fixed lead times.  Since infinite scheduling doesn’t consider the actual limitations of your operation, it generates schedules that don’t let you see when orders will finish.  Also, these infinite schedules are often unachievable.

You can build finite schedules using manual wall boards or spreadsheets.  However, the process is labor intensive and doesn’t handle the change that is inevitable in most manufacturing environments. When circumstances change, the effort required of you to regenerate finite schedules manually is usually prohibitive.

Finite Capacity Scheduling software has evolved to fill the void in your ERP system, and to automate manual methods. The advent of fast affordable computers with graphical user interfaces has made Finite Capacity Scheduling software applicable in a wide range of production environments.

Finite Capacity Scheduling Software helps you:

  • control overtime costs through better visibility to potential problems
  • shorten lead times by scheduling the right work with the proper resources
  • provide better customer service due to the ability to:
    • spot and analyze potential problems while there is still time to take corrective action
    • give better initial delivery commitments to new customers
  • cut inventory and WIP through better controlled production
  • improve utilization and minimize set up by better trading off set up grouping and delivery
  • better justify capital
  • reduce schedule generation times

Finite Capacity Scheduling Software Machine Gantt Chart

The Gantt chart screen view above provides a simple example of scheduling finitely forward in time using FSC software. In the example, first Order_1 in blue and next Order_2 in cyan and red are scheduled forward in time over three machines.  Since the machines are finite, operations of Order_2 must wait to start until after the scheduled finish of the operations of Order_1. The “bottleneck” in this particular example is Machine_2. The time Operation 20 waits to access this machine is what causes Order_2 to be late.

Extensions to Finite Capacity Scheduling Software

Initially Finite Capacity Scheduling software only modeled machine constraints. Over time, the Finite Capacity Scheduling software has evolved to become more full-featured. For example, in job shop scheduling environments, there are often more machines than people. Sometimes multiple operations compete for the same machine, but other times there are multiple operations available to run on multiple different machines simultaneously, but not enough labor to staff the machines. In these environments, machine constraints and labor constraints need to be modeled simultaneously by the Finite Capacity Scheduling software.

In other environments, the Finite Capacity Scheduling software needs to model tooling constraints simultaneously with machine and labor constraints. For instance, in stamping or molding operations, by adjusting tooling inserts, two or more different part numbers may be made from the same die or mold. When one such part number is using the die or mold, another must wait.

Finite Capacity Scheduling software has also evolved to consider materials so that the ordering of materials is synchronized with the scheduling. So, if the scheduling of operations was delayed due to capacity constraints, the corresponding requirement for material could also be delayed. This synchronization of material and capacity supports concepts such as Lean Production Scheduling, and results in steep reduction of inventory. More recent versions of Finite Capacity Scheduling software include even more robust features for modeling materials.

As Finite Capacity Scheduling software has continued to evolve, and become more feature rich, it has become known as Advanced Planning and Scheduling software (APS software).