Product and Process Definition Overview

Items are the basic units produced or consumed during production. Items can be referred to as a part, component, piece, and so on in different manufacturing environments. Define all products, components, and by-products as items for use in the Wonderware MES system.

You can create an item and assign it to an item class and move an item from one class to another and define certifications for an item. To create an item, select the Items module in the Product Definition Group of the Wonderware MES Client. The tabbed workspace shows fields such as Item ID, Item Description, or Item Class.

You can also include the ability to associate a file with an item or assign a certification to an item that is configured in the Wonderware MES Configurator application in the Items module.

Item Classes

Items belong to item classes. An item class is a logical group of items that share common characteristics, such as physical properties and whether they are produced, consumed, or both. Use the Item Classes module to create and maintain an item class. Some examples of item classes are:

• Raw Materials
• WIP Materials
• Finished Goods

Each item can only exist in one item class. Therefore, the organization of the items into classes should be logical to make it easy to filter or search for the items.
When you open the Item Classes module, a list of all the existing item classes is shown in the tabbed workspace. By default, the Item Classes module is grouped under the Product Definition group in the Navigation pane.

Processes and Operations

A process, also known as a route, is the method of producing an item. It is the defined path of manufacturing operations through the plant that will produce a specific final product or by-product. A process definition will link the item to be produced with operations, steps, specifications, physical entities, and routings that determine the flow of material between entities and operations.

An operation defines a task used in the production of an item. It defines the item or items consumed and produced as a result of the task. An operation includes one or more entities used to complete the task and may include labor and machine time estimates. It may also include job specifications and steps. When a work order is created, a job is created for each operation/entity combination.

Processes

A process is a logical representation of the performance of one or more operations utilizing one or more physical entities for the purpose of producing an item. You can create a process to define the

production method to produce an item, and instantiate the work orders. Select the Processes module in the Wonderware MES Client Process Definition group to create and maintain a process and operation.
A process describes the operations and steps required to manufacture an item. A process links an item that needs to be produced with operations, steps, specifications, entities, and routings and determines the flow of material between entities and operations.

Work orders are used to manufacture an item. The use of processes in MES is optional as you can create a work order directly using the Work Orders and Jobs module. Processes are required in the Wonderware MES Client to assign certifications as you cannot assign a certification to a work order.

Operations

An operation represents a phase of a process and specifies the consumption and production proportion. One or more entities are utilized to perform an operation. An operation can have specifications and suboperation step groups. Standard operations are used as templates in the Wonderware MES Client to quickly and easily create similar operation definitions throughout a process.

You can add an operation directed to a process without referring to standard operation. Standard operations save configuration time when the same operation is used multiple times within a process or the same operation is used by multiple processes.

Select the Standard Operations module in the Wonderware MES Client Process Definition group to create and maintain a standard operation. Standard operations do not have items associated with them, so you cannot assign BOM definitions, BOM item specifications, or item specifications to standard operation.

You must assign at least one entity to an operation. Each entity assigned to an operation has an estimated production rate, which you may set. The estimated production rate is used with the batch size to schedule an entity while creating a work order from a process. The required finish date is assigned to the jobs in the last operation and the estimated production rate is used to determine the start time of a job. This process runs until all jobs get a start date and a finish date. If an operation is the first in a process, the batch size specifies the initial amount that is sent to an entity if there is more than one entity in the operation.

Linking items to a process

Production items can be linked to a process. Each item that is linked to a process has its own process status. By default, the status of a linked item is the same as the status of a process. The status of an item must have the minimum required status before a work order is created. An item can have the status as certified for the process while another item has the status as experimental.

By default, status of a process is assigned to an item. You cannot assign a higher status to an item than the status of linked process. If the status of a process is lower than status of the linked item, then status of all items that have higher status is lowered to match the status of the process. For example, if you change status of the process from Approved to Disabled, then status of all the items associated to that process is changed to Disabled regardless of the original status.

A process rank specifies the capability of a process to produce an item. If an item is linked to more than one process, the process with lowest rank for that item is considered as the most preferred process for producing the item.