Introduction

The ArchiMate language for enterprise architecture (EA), and EA in general, is more often associated with information technology (IT) architecture rather than architecture for operational technology (OT).  However, the Physical elements added in the Technology Layer enable versatile OT modeling. This article poses a manufacturing scenario and leads the reader through the corresponding ArchiMate diagram.  It concludes with an example of how ArchiMate modelers can link IT and OT.

Scenario

Central Candy Factory manufactures Chewy Bars, which are individually wrapped candy bars made from bulk chocolate, sweetened shredded coconut and bulk marshmallow.  This Input, which also includes wrappers and boxes for the candy, arrives via the Bulk Food Trucking distribution network.  Central Candy Factory contains a melter that melts the chocolate, a heating mixer that combines the coconut and marshmallows into filling, an extruder that makes cores from filling, and an enrober that makes warm Chewy Bars by covering the cores with melted chocolate.  After spending some time on the cooling rack, the Chewy Bars are placed in wrappers by the wrapping machine, and the Wrapped Chewy Bars are packed in boxes by the packing machine.  This last step yields boxes of Chewy Bars.

ArchiMate Model

Model Narrative

The manufacturing Input is represented as a composite material consisting of five specific materials: Chocolate, Coconut, Marshmallow, Wrappers, and Boxes. The Input flows from the Bulk Food Trucking distribution network to the Central Candy Factory facility. The manufacturing and packaging system is depicted as a series of equipment instances that access materials.  The read access relationship is used to represent the use of inputs by equipment, while the write access relationship is used to represent the production of outputs.  The Heating Mixer uses Chocolate and Marshmallow to make Filling, while the Extruder uses Filling to make Cores. The Melter uses Chocolate to make Melted Chocolate, which the Enrober uses to turn Cores into Warm Chewy Bars.  The Cooling Rack cools down the Warm Chewy Bars to make finished Chewy Bars. The Wrapping Machine uses Wrappers to make Wrapped Chewy Bars, which the Packing Machine packs into Boxes, yielding Boxes of Chewy Bars.

Conclusion: Bridging IT and OT

With only four Physical elements (material, facility, equipment, and distribution network) along with the same ArchiMate relationships used across the Business, Application and Technology layers of the language, modelers can represent a wide variety of OT scenarios.  Using these relationships, ArchiMate modelers can also link Physical elements to the rest of the ArchiMate language, allowing the modeling of scenarios that bridge IT and OT. For example, in the snippet below information flows from a Microcontroller to a Solenoid Assembly, which in turn triggers, i.e., controls, a Gear Set. These relationships are valid ArchiMate since both Device and Equipment are specializations of Node in the ArchiMate Technology layer metamodel and therefore can be linked by the same relationships as their shared parent element.

Authored by Iver Band, EA Principals Senior Instructor and ArchiMate Expert