THE PRODUCT IS NOW AN INTEGRAL PART OF THE PROCESS. GETTING THE DATA FROM THE PRODUCTION PROCESS.
In the previous article we looked at how all "things that are important" (assets) are available in a digital form (key concept in Industry 4.0). We then saw how information can be structured so we can add and retrieve information from it. This in relation with the life cycle value stream. So this means we can add or retrieve information from an asset at any point in its life cycle (so the supplier and customer(s) share information.
In this article we look at the right hand side of the RAMI. We know how to organize the data but where do we get this from. This obviously in relation with the hierarchy level, so how to get all this relevant data to control and steer the production / batch process.
Let take a look how to get the actual data.
The top of the RAMI shows the two (2) standards for production control. To get the information and to control the production typically, sensors, actuators and instruments are used. This is what is listed on the righthand side (bottom) of the RAMI. The hierarchy level shows, in a structured way, how to exchange information (between different “devices”). Since we know how the data is organized (see previous paragraph), the exchange of data can take place in a structured way. Let’s first take a step back to industry 3.0 where retrieving, collecting and storing information was already possible. One of the biggest changes, when comparing to Industry 4.0, is that the functions are bound (connected) to the hardware in industry 3.0. If we look at this in a schematic way (Industry 3.0; the old way), it can be displayed as follows:
Figure 1: Factory hierarchy: the old world (p24) by Platform Industrie 4.0, Berlin, Platform Industrie 4.0.
Before we look at the difference with Industry 4.0, let’s first take a look at the different items listed on the graph (as we need them for Industry 4.0 as well):
Hierarchy level components
Product: the product produced, e.g. a tractor, a washing machine, etc, Notice that “product” is not part of the process but listed separately (in Industry 3.0, it is part of the process in Industry 4.0).
Field Device: electronic devices used for detecting and identifying components and sensor technology, e.g. a pressure sensor, flow sensor, etc.
Control Devices: the brain of manufacturing. Usually in the form of machines/sensors used to manage input/output commands, e.g., programmable logic controller, distributed control system, GUI. So basically, a small control center for a manufacturing process.
Station: administrative activities to monitor the operation of events and processes (e.g. SCADA). The coordination of various products and the results (communication, devices interaction, power generation etc.).
Work center: keeps manufacturing information, defines the production state, and oversees the renovation of raw materials to refined goods.
Enterprise: usually defined in terms of an ERP (Enterprise Recourse Planning), also called business management software. These are core business processes, e.g., production planning, service delivery, marketing and sales, financial modules, retail, and other expenses.
Connected world: this specifically relates to Industry 4.0. this is the top category of all levels and is mainly interlinked with stakeholders, suppliers, customers, and service providers.
Note that Product and Connected World are not part of Industry 3.0. These are included for Industry 4.0. These (two) items are important for industry 4.0 as we (a) want to follow the product across the value chain (different suppliers) and (b) need to a connected world to share and communicate the data. By connecting all assets (see the asset layer on which this is organized), we can follow and share information at any stage of the process. This specifically relates to Industry 4.0.
As a simple example to illustrate the industry 3.0 approach (see image). The control device on the left is used to read out the data from the field device (e.g. flow valve). If another production line also uses a similar sensor, a new control device is introduced (obviously a copy of the software can be made). But it would introduce two copies which in turn introduce a revision problem (how to manage changes made to one control device). In industry 4.0, functions are “clustered”, available at a central location and can be used from this central location when needed.
Industry 4.0 “Hierarchy levels”
Things are organized differently in Industry 4.0. Since we have specified the functions for each asset (see the layers paragraph), we are not bound (limited / restricted) to specific hardware to perform a function.
If we have defined a specific function to collect data and present this in a graphical form, we can use (call) this function each time it is needed. The same functional can be used for various products, we just need to store the function in a central location (e.g. cloud based) and use (call) it whenever we need it.
Since the product (that is being produced) also has a virtual representation (e.g. digital twin), information can be saved and retrieved from and to it. The product is part of the information world.
Figure 1: Factory hierarchy: the new world (p25) by Platform Industrie 4.0, Berlin, Plaform Industrie 4.0.
In the graph above we see two (2) products being produced, a tractor and a washing machine (left hand side). Both products use an electric motor (e.g. for movement of a certain part). The electric motor is a physical product (and an asset with a virtual representation) and the information (necessary data) about this motor is available. This means the electric motor holds specific information that can be (re-)used*2.
*2 this may also include information from the supplier (value chain), we look at this later.
Every time we use this electric motor, we can pull the information from the “information layer” (e.g type of motor, operating conditions, shaft size, etc). As the information is organized and structured, it can be pulled from the asset. We know, for example, what the shaft size is or the operating conditions for that specific motor.
For correct installation and operation of the electric motor in the final product, we can use a control device (e.g. sensor measuring torque). The control device can pull information from the information layer (e.g. settings for correct torque measurement) to ensure correct installation and operation of the motor. During the manufacturing process information about the installation of the motor in the product (e.g. tractor or washing machine) can be stored back.
Since we have a virtual (digital) representation of an asset and the information including its functions is available (layers stage) and the information is available as defined at the hierarchy levels; we can “connect” everything together. Information can be collected and stored from and to a central point.
With the “Connected world” available we can exchange information also with suppliers and customers.
The next article is available, dealing with the types and instances, how can we control the changes and support efficiency in the development and production.