A production schedule is only achievable if the required materials are available when work begins. MxAPS accounts for inventory availability during scheduling, ensuring that operations are scheduled only when the necessary components are expected to be available.

By considering material constraints alongside machine capacity, routing dependencies, and calendars, MxAPS produces schedules that are both optimized and realistic.

Why Inventory Matters

Every production operation requires materials before it can begin.

If required inventory is unavailable, starting the operation would result in production delays or work stoppages. Instead, MxAPS delays the operation until the required materials are expected to be available.

This allows the generated schedule to reflect what can actually be produced, rather than simply filling machine time.

How Inventory Affects Scheduling

When MxAPS evaluates an operation, it determines the earliest time that production can begin by considering multiple constraints, including:

• Required inventory
• Machine availability
• Routing dependencies
• Working calendars
• Other scheduling rules

Production can only begin when all required constraints have been satisfied.

If inventory is the limiting factor, the operation is automatically delayed until the required material is available.

Sources of Inventory

MxAPS can consider inventory supplied from several sources, including:

• Current on-hand inventory
• Purchase Orders
• Production Orders
• Transfer Orders
• Other replenishment activities recognized by the scheduling engine

As additional supply becomes available, dependent operations can be scheduled accordingly.

Example: Waiting for Purchased Material

A production order requires a purchased component that is not currently in inventory.

Time	Event
Monday	Production order released
Tuesday	Purchase Order expected to arrive
Wednesday	Machine available

Although the machine is available on Monday, production cannot begin until the purchased material arrives.

MxAPS schedules the operation after the expected receipt of the required inventory.

Example: Waiting for an Upstream Production Order

Inventory constraints also apply when one production order supplies another.

Suppose:

• Production Order A manufactures a subassembly.
• Production Order B consumes that subassembly.

Even if the machine assigned to Production Order B is available earlier, MxAPS delays the downstream operation until Production Order A has completed and the required inventory is available.

This allows dependent production orders to be scheduled in the correct sequence automatically.

Recognizing Material Constraints in the Schedule

Material shortages are reflected naturally in the schedule.

Rather than displaying a separate warning or icon, MxAPS simply schedules operations at the earliest feasible time.

As a result, you may observe:

• operations beginning later than expected
• gaps before production starts
• idle periods on resources waiting for material

These schedule gaps often indicate that inventory availability, rather than machine capacity, is preventing production from starting sooner.

Inventory Is One of Several Scheduling Constraints

Inventory is only one factor considered by the scheduling engine.

MxAPS also evaluates:

• resource availability
• routing precedence
• setup optimization
• calendars and working time
• scheduling rules and constraints

The scheduled start time for an operation is the earliest point at which all applicable constraints have been satisfied.

For example, even if inventory is available immediately, an operation may still be delayed because:

• the required machine is already occupied,
• a predecessor routing operation has not yet completed, or
• setup optimization results in a more efficient production sequence.

Benefits of Inventory-Aware Scheduling

Considering inventory during scheduling helps produce schedules that are more practical and achievable.

Benefits include:

• Reduced production interruptions caused by missing material.
• More realistic production dates.
• Better visibility into the impact of supply delays.
• Improved coordination between purchasing, manufacturing, and production planning.
• Schedules that account for both capacity and material availability.

By scheduling operations only when the required inventory is expected to be available, MxAPS helps planners generate production schedules that better reflect actual shop floor conditions.