INSTANCE AND TYPE.
CONTROLLING AND COMMUNICATING BETWEEN PARTNERS IN THE VALUE CHAIN
We worked our way through the “procedures” to define how information is collected and stored for the assets (layers). We also reviewed how we can get and share information from the production processes (hierarchy). We can now take a look on how we can follow and control an asset through the value chain (supplier to customer). Let's start by looking at the RAMI model:
In this article we specifically look at the bottom part, the Type and Instance.
Development, type, production and instance
This part is specified at the bottom of the RAMI model where we see “type” and “instance”. Both type and instance have a reference to ‘Development’ and ‘Maintenance Usage’. This may be confusing at first, so let’s dive into this.
What this basically states is that there are two (2) separate phases for a product, the
(a) development phase (type)
(b) production phase (instance)
“Instancing” is a term very commonly uses in programming where multiple objects (from a reference asset) are created through “instancing”. For none IT users, you can arguably say that a copy is made. Once the development is completed, the data (maintenance and usage) for the asset is collected and stored (dimensions, drawings, characteristics, etc).
The asset will then go into production where an “instance” of the product is created. Once created, data (maintenance and usage) is collected for the produced parts (e.g. load values, test parameters, etc). Since we can follow the asset through the value chain, the data available from the asset can be used by a customer (as they use the asset in their production process).
If during the production process errors are found or improvements are established, this information can be fed back to the development team (type) and be included. The type can then be updated (and a new type will be instantiated when needed).
But the same applies for other business channels. Suppose a system integrator (machine builder) uses the part which is produced earlier by the supplier. During the development phase (e.g. machine design) data about the electrical motor can be provided (e.g. CAD drawing). Once the motor is used in the assembly process of the system integrator and any error or improvement is found, this can be communicated back to the company that developed and produced the electrical motor.
Examples of Type and Instance communication
Let's take a look at an example. We see a producer of electrical motors on top. They supply the motor to a system integrator that creates assembly automation (robot and packing systems). These systems are sold to a producing company that uses various of these assembly automation systems for the production and packing of their goods (e.g. bags of french fries or the packing of cookies).
All data was first gathered by development department of the company that produced the motor (maintenance usage of the type). It was then produced (becoming an instance) and data was added from the production department. Once fully completed the motor was shipped out and integrated with an automation system. During testing and evaluation the system integrator found that when they use the motor in a dedicated mode (e.g. speed or load characteristic) the motor experiences damage and does not work correctly anymore.
They can then apply for service of the parts (since all data is logged the producer of the motor has all information about the motor) and the information can also be provided to the development team of the motor producers to investigate and update. All data is fed back to the producer to avoid the same error happening again. Both development team and service team at the motor producer can work on the issue.
The production data of the motor can also be gathered at the end user to better understand the conditions under which the motor is used and how it is used. This data can also be fed back to the producers of the motor (directly) to provide feedback on the behavior during production. This data can be used by the (e.g.) development team at the motor producer to evaluate, provide updates or service plans.
With all data available (and controlled), information can be shared more easily in the value chain (supplier and customer) resulting in greater efficiency.
How can we communicate with an asset to store and retrieve information? To achieve this, Industry 4.0 uses the Asset Administrative Shell (AAS).