Quantity Variation#

This tutorial provides an overview of the different ways the quantity of a BOM Item can be defined and configured in Critical Manufacturing MES. It covers quantities dependent on the main Material, fixed quantities, negative quantities for by-products, as well as specific configurations such as quantity tolerances and reference items.

Overview#

This tutorial will explain the key concepts related to how BOM Item quantities can be defined and managed, including:

• BOM Item consumption dependent on main Material quantity - where the required quantity scales with the quantity of the main Material.
• BOM Item consumption with fixed quantity - where the required quantity remains constant, regardless of the main Material quantity.
• BOM Item consumption tolerances - allowing flexibility in meeting exact quantity requirements.
• Negative quantity (by-products) - where the BOM defines Materials produced as a result of the process.
• BOM reference Items - used for reference or informational purposes without consumption in MES.
• Option to capture - enabling the recording of specific values or details during assembly.

The tutorial concludes with a practical use case that brings these concepts together, demonstrating their application and the necessary configurations to support them.

Dependent Quantity#

The dependent quantity configuration is the most common approach for BOM Items. In this scenario, the required quantity of a BOM Item is directly proportional to the quantity of the main Material being assembled.

This behavior covers situations where, for example, assembling 1 unit of a main Material of a given Product requires X units of a specific consumable Product.

Main configuration requirements:

• Units of the Product to be assembled
• BOM Item Products and their substitutes
• Amount of BOM Item units to be consumed

Fixed Quantity#

The fixed quantity configuration applies when the required amount of a BOM Item is constant, regardless of the main Material quantity being processed.

For example, a quality test kit might be included with the Product. Whether 1 or 100 units are assembled or tested, only a single kit is added for the final customer. This applies for Assemble, Disassemble and Replace & Disassemble operations, and is also considered for Material Transfer Requirements and BOM Explosion.

Main configuration requirements:

• Units of the Product to be assembled
• BOM Item Products and their substitutes
• Amount of BOM Item units to be consumed
• Assembly Type must be Explicit Long Running, Automatic at Track-In or Automatic at Track-Out

Tolerances#

Tolerances allow for flexibility in BOM Item consumption, enabling the recorded consumed quantity to differ from the theoretical quantity. This is available for BOMs with the Materials scope with manual assembly types, and is in use by default in BOM Weigh and Dispense.

This supports use cases, as for example: an industrial air conditioning unit BOM specifies 1.2 m² of insulation foam based on CAD measurements. In practice, operators may use 1.6-1.8 m² due to manual cutting inaccuracies or overlapping pieces to ensure coverage.

Main configuration requirements:

• Units of the Product to be assembled
• Use Tolerances property set to true
• BOM Item products and quantities
  • Lower and upper tolerance values (percentage-based set from 0 to 100) for all BOM Items
  • If the Product is discrete, tolerances are not supported or required
• Substitute BOM Products, where applicable

Regarding the Disassemble operation, the calculated quantities are the theoretical ones, and tolerances are applied in order to allow the user to disassemble the same quantity that was assembled before. Regarding the Replace, BOM Item tolerances are applied to the quantity available for replacement.

Negative Quantity#

Negative quantities support scenarios where the production process also produces by-products that need to be tracked in the system. This applies to BOMs with the Materials scope only. Also, Transfer Requirement for material ignore the negative BOM Item and it is not possible to add negative BOM Item for Material deviation in a Checklist.

The key difference from normal BOM Items is that consumption happens in reverse: the by-product quantity increases during assembly and decreases during disassembly.

To illustrate an example, consider a juice production, where processing fruit yields peel by-products. These peels may be collected for essential oil extraction or biofuel production.

Main configuration requirements:

• Units of the Product to be assembled
• BOM Item Products, no substitutes are not allowed for negative BOM Items
• Negative quantity value representing the by-product yield

Reference Items#

A reference item is a BOM Item which consumption is not recorded in MES. It is included purely for informational or display purposes within the BOM, ensuring that relevant, non-consumable items are visible in the assembly context.

Main configuration requirements:

• Units of the Product to be assembled
• BOM Item Products and their substitutes
• Flag option IsReference set to True for the Reference Items
• Any informational quantity (optional, since it will not be tracked in the system)

Option to Capture#

The Option to Capture setting is independent of whether the BOM Item is to be consumed or is just a reference. It enables the collection of specific data during assembly, which is associated with the BOM Item.

This feature is available for BOMs with Materials and Parts scope. It does not apply to substitutes, which inherit the capture settings from the main BOM Item.

There are some use cases where this feature might be relevant:

• Capturing lot, batch, or serial numbers for traceability, with or without actual consumption.
• Recording details for external components not tracked as materials in MES, such as cable ties used in machine assembly.
• Enforcing manual entry of specific data during the assembly of certain components.

Main configuration requirements:

• Units of the Product to be assembled
• BOM Item Products and their substitutes
• Enable the Information Capture Required field for the item, and set the Information Capture data

Use Case#

For this use case, a more specific manufacturing context will be presented, as these concepts are easier to assimilate with a actual production process.

Consider a manufacturing company that assembles Industrial Coffee Machines (Product: CMC-5000). Each unit requires a set of components, some of which are consumed proportionally to the quantity of machines, while others are fixed.

The process may also produce by-products, allow tolerances for certain components, include items for reference only, or require optional data capture for traceability.

At the final stages of the production processes, the following steps and requirements must be considered:

For simplicity, the overlaying structure includes a general Service provided by a shared Resource, which is required by all Steps.

In addition, there is a storage Flow and a Step dedicated to gathering all component Materials.

Configuration#

Basic configurations like Calendar, Facility, Area, Resource, and Service are assumed to be pre-defined and are not detailed here.

Steps and Flows#

The general configuration of the sequential main production Flow and Step is detailed in the images below.

The general configuration of the sequential storage Flow and Step is detailed in the images below.

A few details worth mentioning are the following:

• The property IsDecimalQuantityAllowed is set to true for the Storage Step as this Step will deal with decimal quantities for Materials of the Product Thermal Insulation Foam and Coffee Grounds Waste.
• Both Storage and Machine Flows are sequential.

Product#

For this scenario, six Products are considered:

The general configuration of the Products is detailed in the images below.

BOM#

The BOM is configured to be of scope Materials, and to use tolerances. The details to consider for each BOM Item are the following:

The configuration of the BOM and BOM Items can be found in the image below.

• The Use Mixed Assembly property is set to false.
• The BOM is configured with the Materials scope.
• The Base Quantity property is set to 1.

BOM Context#

For each Step, when a Material of CMC-5000 Product is tracked in, the CMC-5000 BOM will be triggered, and each Step has its own assembly type.

The configuration of the BOMContext Smart table is presented in the table below.

The master data file supporting this use case is available here: XML File.

Execution#

To begin this scenario, a Material must exist for each BOM Item that is not marked as a reference (for example, all BOM Items except the User Manual Product). These Materials must be available at the Storage Step of the Storage Flow, with sufficient quantity to fulfill the demand of the main Material.

In addition, a Material with a quantity greater than 0 must exist to simulate the production of a CMC-5000 Product. This Material should be placed at the Grinder Assemble Step of the Machine Flow.

Grinder Assemble Step:

1. Dispatch and Track-In the CMC-5000 Material.
   • The BOM information for the BOM Item Coffee Grinder Module and its required quantity is displayed.
2. Perform Assemble.
   • Select the component Material.
   • The system prompts for the Serial Number, as defined in the configuration.
   • Once assembled, it is possible to perform Disassemble or Replace.
3. After the full Material quantity is assembled, Track-Out and Move Next.

Thermal Insulation Step:

1. Dispatch and Track-In the CMC-5000 Material.
   • The BOM information for the BOM Item Thermal Insulation Foam and its required quantity is displayed.
2. Perform Assemble.
   • Select the component Material.
   • Since this BOM Item has tolerances, the user may assemble a quantity within the allowed range (up to 50% above the theoretical requirement).
   • Because this step uses the Explicit Assembly type, it is also possible to disassemble quantities within the defined tolerances, as explained above.
3. After the full Material quantity is assembled, Track-Out and Move Next.

Machine Testing Step:

1. Dispatch and Track-In the CMC-5000 Material.
   • The BOM information for the BOM Item Coffee Grounds Waste and its expected quantity is displayed.
2. Perform Assemble.
   • Select the component Material.
   • As this BOM Item represents a by-product, the quantity of the source Material increases when assembled.
   • Once assembled, it is possible to perform Disassemble or Replace.
3. After the full Material quantity is assembled, Track-Out and Move Next.

Boxing Step:

1. Dispatch and Track-In the CMC-5000 Material.
   • The BOM information for the BOM Items User Manual and Water Quality Test Kit, along with their required quantities, is displayed.
2. Perform Assemble.
   • For the User Manual, marked as a Reference BOM Item, no source Material is required.
   • For the Water Quality Test Kit, configured with a fixed quantity of 1, only one kit is consumed/assembled regardless of the main Material quantity.
   • Once assembled, it is possible to perform Disassemble or Replace.
3. After the full Material quantity is assembled, Track-Out.