Overview of Constraint-Based Supply Planning

With constraint-based supply planning, you can create and run supply plans that consider material and capacity constraints. Constraint-based planning improves productivity by automating the process of applying lead time and supplier capacity constraints to make planning decisions.

You can focus on meeting demand on time by evaluating all possible alternatives, such as using different sources, substitute components, or alternative work definitions.

A constrained supply plan respects constraints by moving orders to earlier time buckets or offloading to an alternate resource, work definition, or supply source. If these measures are insufficient, then the constrained supply plan, as a last resort, overloads resource and supplier capacity to meet demands on time. In this sense, resource and supplier capacities are soft constraints that the planning process violates only when necessary.

In contrast to the soft constraints, a constrained supply plan in general treats lead times as hard constraints. A demand suddenly arising inside of manufacturing or procurement lead time causes the constrained supply plan to fulfill the demand late. An exception to this rule can be made for buy supplies. If the Enforce Purchasing Lead Time item attribute is set to No, then the supply planning process compresses the purchasing lead time to meet demands on time.

Now, you already know that to create a plan, the first thing that you do is define your plan options. For constraint-based supply planning, you must set the Supply Planning Mode to Constrained when you create your plan. You can specify the constrained mode only for a supply plan type or a demand and supply plan type. There are additional plan options that drive planning behavior for a constrained supply plan.

Plan Options page, Scope tab, Plan Parameters section: Specify a combination of bucket types to define the planning horizon of a constrained plan.
Plan Options page, Supply tab, Constraints and Decision Rules subtab.
- Specify capacity constrained resources to indicate how your plan applies capacity constraints to resources.
- Specify whether to apply supplier capacity constraints.
- Select the types of alternate sources of supply that your plan can evaluate if the primary source of supply is unable to meet demand on time.
Supply: Plan Options dialog box, Optimization Parameters tab: Don't change these default values unless advised to do so by your Oracle help desk.

Run a Constrained Supply Plan

Unlike unconstrained plans that can be run in interactive mode or in batch mode, you can only run a constrained plan in batch mode.

Constraint-Based Supply Planning Behavior

Here are some important points about the constraint-based planning behavior.

In constraint-based supply planning, supply quantity is determined based on capacity within the processing lead time.

In unconstrained planning, the supply quantity is determined first and then the lead time of the supply is calculated using fixed and variable lead times.
Internal lead time rollup is used to determine the Processing Lead Time of items with order modifiers, if the user-specified value isn't feasible.

For example, suppose that an item has a fixed order quantity of 100, and based on the routing-level processing time, the time required to make 100 units is 5 days.
- If the processing lead time for the item is 3 days, the planning process uses 5 days as the lead time since it's not feasible to make 100 units in a 3 day lead time.
- If the processing lead time for the item is 7 days, the planning process uses 7 days as the lead time since the user-specified value is more than the value calculated by the internal lead time rollup.

Prioritization of Demand

Demands are prioritized in a particular sequence in a constrained supply plan. This prioritization drives decisions made in constrained planning on how existing supplies such as on-hand supplies are allocated to meet competing demands.

Sales orders by schedule date
Sales orders by request date
Sales orders by order value
Forecasts by suggested due date
Forecasts by order value