standards The world of 'Digital Twin Uses' delivered in standard terms

[Ramy]

The idea of a Digital Twin [DT] needs to advance in a standardized and formal manner. As @DRossiter87 pointed out, this is necessary to "support the consistent adoption of, and interoperability between, digital twins for the built environment within the UK"

To aid in this endeavour, it is useful to delineate the difference between the following terms:

“DT General Use Case” [GUC]: a very short sentence, possibly consisting of two or three words – ideally a verb followed by a noun – ultimately concerned with the brief and blunt statement of the central business aim that is motivating the use and implementation of a DT, e.g., ‘optimize traffic’.

“DT Use Case Scenario” [UCS]: a documentation of the sequence of actions, or in other words, DT-user interactions executed through a particular DT case study or an actual DT real-world project.

“DT Use”: a typical technical function or action executed by any DT throughout the course of any UCS. Accordingly, the DT uses are seen as the standard building blocks by which a standard common language can be founded. Such a standard language, which can possibly be machine-readable as well, can be used in documenting and detailing the DT-user interactions in a standard format to facilitate their publishing and sharing of knowledge.

Below is a figure of a “DT uses taxonomy”. It is made up of three distinct hierarchical levels, these are respectively:

• ‘Included Uses’ containing four high-level cornerstone uses that are, besides rare exceptional cases, included in and executed by almost every DT throughout any UCS (i.e. Mirror, Analyse, Communicate and Control);
• ‘Specialized Uses’ including special forms of the Included Uses, where each specialized use enjoys unique strengths suitable for specific purposes; and
• “Specialized Sub-Uses” at the lowest hierarchical level of the taxonomy, which further differentiates between variant types within a Specialized Use at the higher level by virtue of very fine inherent variations that distinguish one type from another and thus, enhances the DT’s practical adequacy in dealing with alternative contexts and user specifically defined purposes.

 

The table below include a formal definition of each DT Use.

 

DT Use			Definition	Synonyms
01	Mirror		To duplicate a physical system in the real world in the form of a virtual system in the cyber world.	Replicate, twin, model, shadow, mimic
	1.1	Capture	Express in a digital format within the virtual world the status of a physical system at a point of time. (Usually, offline DT)	collect, scan, survey, digitalize
	1.2	Monitor	Collecting information related to the performance of a physical system. (Online or Offline DT)	Sense, observe, measure
	1.3	Quantify	Measure quantity of a physical system’s particulars, instances or incidents. (Online or Offline DT)	Quantify, takeoff, count
	1.4	Qualify	Track the ongoing status of a physical system (Online or Offline DT)	Qualify, follow, track

DT Use				Definition	Synonyms
02	Analyse			To create new knowledge and provide insights for users and stakeholders about a physical system.	Examine, manage
	2.1	Compute		To perform conventional arithmetical calculations, traditional mathematical operations and functions and simple statistical techniques like correlations	Calculate, add, subtract, multiply, divide
	2.2	Mine		To uncover, identify and recognize the web of interdependencies, interconnected mechanisms, complex processes, interwoven feedback loops, masked classes, clusters or typologies, hidden trends and patterns within the physical system.	Learn, recognize, identify, detect, AI, ML, BDA
	2.3	Simulate		To explore and discover the implications and possible emerging behaviours of a complex web of interacting set of variables.
		2.3.1	Scenario	To find out the implications, impacts or consequences of implementing pre-defined scenarios (akin to non-destructive tests)	What-if, evaluate, assess
		2.3.2	Stress-Test	To identify the scenarios that may lead to failure or breakdown of physical system (akin to destructive tests)	Test, inspect, investigate
	2.4	Predict		Concerned with futures studies
		2.4.1	Forecast	to predict the most likely state of a real system in the future, by projecting the known current trends forward over a specified time horizon.	foresee
		2.4.2	Back-cast	To question or prove in a prospective manner, how the physical system is operating towards achieving the pre-set aims and goals.	manage, confirm
	2.5	Qualitize		Enhance and improve the quality of the outcomes or deliverables produced by an intervention in real world.
		2.5.1	Verify	Verify conformance and compliance of physical system with standards, specifications and best practice.	Validate, check, comply, conform
		2.5.2	Improve	Inform the future updating, modifying or enhancing the current standards to be in better coherence and harmony with the actual operational and usage behaviours and patterns.	Update, upgrade, revise

DT Use			Definition	Synonyms
03	Communicate		To exchange collected and analysed information amongst stakeholders.	interact
	3.1	Visualize	To form and vision a realistic representation or model of current or predicted physical system.	review, visioning
	3.2	Immerse	To involve interested stakeholders in real-like experiences using immersive technologies such as VR, AR and MR.	involve
	3.3	Document	Document and represent gathered and/or analysed data in a professional manner and technical language, forms or symbols.	Present
	3.4	Transform	To modify, process or standardize information to be published and received by other DT(s) or other DT users (e.g. a National DT) or overcome interoperability issues	Translate, map
	3.5	Engage	To involve citizens and large groups of people including marginalized groups in policy and decision-making processes.	Empower, include

 

DT Use			Definition	Synonyms
04	Control		To leverage the collected and analysed information to intervene back into the real world to achieve a desirable state.	Implement, execute
	4.1	Inform	To support human decision making throughout the implementation of interventions in the real world.	Support, aid
	4.2	Actuate	Using CPS and actuators to implement changes to physical system.	Regulate, manipulate, direct, automate, self-govern

 

Standardised set of ‘DT Uses’ can help avoid miscommunication and confusion while sharing or publishing DT Use Case Scenarios and their content explicitly explaining the 'know-how'. It can also support the procurement of DT services by ensuring the use of a one common language across the supply chain and stakeholders.

 

Al-Sehrawy R., Kumar B. @Bimal Kumarand Watson R. (2021). Digital Twin Uses Classification System for Urban Planning & Infrastructure Program Management. In: Dawood N., Rahimian F., Seyedzadeh S., Sheikhkhoshkar M. (eds) Enabling The Development and Implementation of Digital Twins. Proceedings of the 20th International Conference on Construction Applications of Virtual Reality. Teesside University Press, UK.

Edited February 11, 2021 by Ramy