**1. Introduction**

The end of the second decade of the twenty-first century has witnessed a growing diversity of devices and information processing which smart buildings and cities are introducing into vertical (now also 'two-dimensional', c.f. thyssenkrupp elevator MULTI [1], and maybe 'three-dimensional' in the future [2]) building transportation systems. A new generation of lift systems has been developed offering increased levels of personal response particularly as a result of supporting destination call registration. This has been accompanied by increasing sophistication and variety of human interfaces, for users in many roles. Also there has been a rapid expansion of cloud-based analysis services, using Artificial Intelligence, that are capable of managing and processing vast amounts of data. The Internet of Things (IoT) is a key enabler of this technology evolution, so a section is included providing an overview of the IoT with the further objective of clarifying this somewhat misused appellation.

The variety of information domains and related equipment and service suppliers involved in these developments makes it increasingly important to conform to an agreed standard vocabulary and associated set of rules for interchange of information – a schema – that is specific to the application domain i.e. transportation systems in buildings.

Indeed the design and configuration of such systems would be enhanced considerably if such a schema was to be implemented internally as a foundation information model as well as for external communications. The continuing practice adopted by manufacturers of implementing proprietary communications, while promoting vendor lock-in, is no longer viable when travellers, administrators, owners, technicians, etc. experience many points of contact with such a variety of systems from disparate suppliers – For example, users cannot be expected to select the application of the lift manufacturer or maintenance company in whose lifts they wish to travel to register a call from their personal mobile device! However, the need for a common shared information model extends far beyond this trivial example and is relevant to most aspects of the operation of building transportation systems, particularly when machines are communicating directly with other machines without human interpretation of the exchanged information.

The Standard Elevator Information Schema (and complimentary Escalator Schema) which defines the information model is a formal declaration of the elements, their properties, interrelationships and validation rules and is directly meaningful to both humans and machines ('things').
