Difference between revisions of "MRO Material Management"

Revision as of 14:46, 18 June 2026

MRO Material Management

MRO material management is used to support maintenance work with the required spare parts, consumables, tools, or other material items.

In a maintenance workflow, users may need to know:

• which material is required for a task
• which material master data belongs to a material
• where the material is stored
• how much material is available
• how much material is already reserved
• which reservations exist for a task
• whether a reservation is planned, confirmed, issued, cancelled, or expired

The material management implementation separates the general material catalogue from the actual material quantity and reservation handling.

Basic concept

The material management implementation is built around the following main objects:

Object overview

GoodsMovement

Purpose

GoodsMovement is the base class for material-related quantity-bearing objects.

It defines the common quantity concept used by both:

• Material
• Reservation

Important properties

MaterialMaster

Purpose

MaterialMaster represents the material master or catalogue entry.

It stores item-level master data that can be referenced by material instances in MRO.

A material master describes the material independently from a concrete reservation or task.

Important properties

Material type

The typed material type accessor is MaterialType.

Known values are:

• SpareParts
• Consumables
• Tools

Material

Purpose

Material represents a material instance or stock entry in MRO.

It inherits from GoodsMovement and therefore uses the inherited QUANTITY property as its material quantity.

A material links to:

• a material master via LK_MATERIAL_MASTER
• a storage location via LK_STORAGE_LOCATION

It also exposes calculated reservation and availability logic.

Important properties

Material status

The material status is stored in MATERIAL_STATUS and exposed through the typed accessor MaterialStatus.

Known values are:

Reserved quantity

RESERVED_QUANTITY is calculated at read time.

The calculation uses reservations where:

• LK_MATERIAL points to the current material
• STATUS is ReservationStatus.Confirmed

The calculated value is the sum of QTY_PLANNED of these confirmed reservations.

Available quantity

The available material quantity is calculated by the method AvailableQuantity().

Active reservations

The method HasActiveReservation() checks whether active reservations exist for the material.

It queries reservations where:

• LK_MATERIAL points to the current material
• STATUS is lower than or equal to ReservationStatus.Confirmed

This means the method considers reservations up to the confirmed state as active.

Delete behavior

Material.InternalDeleteAllowed() prevents deleting a material if it still has quantity or active reservations.

Deletion is only allowed if the base delete conditions are fulfilled and:

• QUANTITY is lower than or equal to 0
• HasActiveReservation() returns false

Reservation

Purpose

Reservation represents a material reservation for a task.

It links:

• a task via LK_TASK
• a material via LK_MATERIAL

It stores the planned reservation quantity in QTY_PLANNED and can also store an actual quantity through the overridden QUANTITY property.

Important properties

Reservation status

The reservation status is stored in STATUS and exposed through the typed accessor Status.

Known values of ReservationStatus are:

Status change rules

Status changes are controlled by AllowStatusChange(int newStatus).

The following rules are applied:

• no status change is allowed when the current status is Issued
• changing from Confirmed back to Planned is not allowed
• other status changes are allowed by this method

Planned quantity validation

The setter of QTY_PLANNED validates changes through AllowQuantityPlanned(double).

A new planned quantity is only allowed if:

• Status is ReservationStatus.Planned
• LK_MATERIAL is assigned
• the new quantity is greater than 0
• the new quantity is lower than or equal to LK_MATERIAL.AvailableQuantity()

Actual quantity validation

The overridden QUANTITY setter validates changes through AllowQuantity(double).

A new actual quantity is only allowed if:

• the new quantity is greater than 0
• the status is either Planned or Confirmed

Link editing rules

The setters of LK_TASK and LK_MATERIAL are guarded by reservation status.

The links cannot be changed when the reservation is:

• Issued
• Confirmed

This prevents changing the task or material after the reservation has reached a more binding status.

StorageLocation

Purpose

StorageLocation represents a physical storage location.

It is a functional location specialization and can be linked from Material via LK_STORAGE_LOCATION.

A storage location stores information about storage type, dimensions, access type, label, level, position, and occupancy.

Important properties

Storage type

Known values of StorageType are:

• Floor
• Shelf
• Rack
• Bin
• Pallet
• Container

Access type

Known values of AccessType are:

• Manual
• Forklift
• Crane
• Automated

Occupancy status

Known values of OccupancyStatus are:

• Empty
• Partial
• Full
• Reserved
• Blocked
• OutOfService

Relations

The following relations are relevant for material management.

Quantity concepts

Material quantity

The material quantity is stored in Material.QUANTITY.

Because Material inherits from GoodsMovement, the property is inherited from the base class.

Reserved quantity

The reserved quantity is exposed through Material.RESERVED_QUANTITY.

It is calculated by summing the QTY_PLANNED values of confirmed reservations for the material.

Only reservations with Status equal to ReservationStatus.Confirmed are included in this calculation.

Available quantity

Available quantity is calculated by Material.AvailableQuantity().

Planned reservation quantity

The planned reservation quantity is stored in Reservation.QTY_PLANNED.

It can only be set if:

• the reservation is still Planned
• a material is assigned
• the quantity is greater than 0
• the quantity does not exceed the material's available quantity

Actual reservation quantity

The actual reservation quantity is stored in Reservation.QUANTITY.

This property overrides GoodsMovement.QUANTITY and can only be set if the status is Planned or Confirmed and the new quantity is greater than 0.

Quantity overview

Reservation workflow

Creating or editing a reservation

A reservation links a material to a task.

For a reservation to define its planned quantity correctly:

1. LK_MATERIAL must be set.
2. LK_TASK should point to the task requiring the material.
3. Status must still be Planned.
4. QTY_PLANNED must be greater than 0.
5. QTY_PLANNED must not exceed LK_MATERIAL.AvailableQuantity().

Confirmed reservations

When a reservation is confirmed, it contributes to the material's reserved quantity.

This affects the available quantity of the material because:

Finishing a task

When a task is finished, the task logic calls CloseReservations().

The method processes active reservations for the task:

• if a reservation has status Confirmed, it is set to Issued
• otherwise, it is set to Cancelled

The changed reservations are added to the unsaved children through AddToUnsavedChildren(reservation) so that the changes are persisted.

Usage in tasks

Reservations are the central link between material handling and task execution.

A reservation connects:

• the required material through LK_MATERIAL
• the task through LK_TASK
• the planned quantity through QTY_PLANNED
• the reservation state through Status

This means that material usage is tracked at task level in the inspected implementation.

Goods movement usage

GoodsMovement is the common base class for quantity-bearing material objects.

Both Material and Reservation inherit from it and expose QUANTITY.

In the inspected implementation:

• Material.QUANTITY represents the material quantity
• Reservation.QUANTITY represents the actual quantity for the reservation and applies reservation-specific validation
• Reservation.QTY_PLANNED represents the planned reserved quantity
• Material.RESERVED_QUANTITY is calculated from confirmed reservations

Example workflow

Scenario

A task requires one spare part from stock.

Step 1: Material master exists

The spare part is defined as a MaterialMaster.

Step 2: Material exists in a storage location

A Material object references the material master and a storage location.

Step 3: Reservation is created for a task

A Reservation links the material to the task.

The planned quantity is allowed because the material has enough available quantity.

Step 4: Reservation is confirmed

The reservation status is changed to Confirmed.

After confirmation, the material's reserved quantity includes the reservation's planned quantity.

Step 5: Task is finished

When the task is finished, CloseReservations() is called.

The confirmed reservation is changed to Issued.

Validation and business rules

The following business rules are implemented in the inspected material management logic.