Promise theory

[2] Promise theory is being used in a variety of disciplines ranging from network (SDN)[3] and computer systems management[4] to organizations[5] and finance.

[7] A collaboration between Burgess and Dutch computer scientist Jan Bergstra refined the model of a promise, which included the notion of impositions and the role of trust.

[1][6][8][9][10][11][12][13] In spite of wider applications of promise theory, it was originally proposed by Burgess as a way of modelling the computer management software CFEngine and its autonomous behaviour.

CFEngine had been under development since 1993[4] and Burgess had found that existing theories based on obligations were unsuitable as "they amounted to wishful thinking".

[14] Consequently, CFEngine uses a model of autonomy - as implied by promise theory—both as a way of avoiding distributed inconsistency in policy and as a security principle against external attack.

In the essay Promise You A Rose Garden (2007)[14] Burgess used a more popular, less academic style, but it failed to widen the general visibility of the concept at the time.

A few years later, in 2012, things changed when Cisco began using promise theory in their growing SDN initiatives, also known as Application Centric Infrastructure (ACI).

[16] The tech media picked up the usage in 2013,[17][3][18][19] which led to a number of applications of promise theory in new disciplines in the years following, such as biology,[20] supply chain management,[21] design,[22] business/leadership[23][5] and systems architecture.

[25] Promise theory is described as a modeling tool or a method of analysis suitable for studying any system of interacting components.

This independence implies that they cannot be controlled from without, they originate their own behaviours entirely from within, yet they can rely on one another's services through the making of promises to signal cooperation.

The promise of door handleness could be expressed by virtue of its physical form or by having a written label attached in some language.

[27] While still dominant, the obligation based model has known weaknesses, in particular in areas like scalability and predictability, because of its rigidness and lack of dynamism.

Although this assumption could be interpreted morally or ethically, in promise theory this is simply a pragmatic engineering principle, which leads to a more complete declaration of the intended roles of the actors or agents in a system: When making assumptions about others' behaviour is disallowed, one is forced to document every promise more completely in order to make predictions, which in turn will reveal possible failure modes by which cooperative behaviour could fail.

[6] In computer science, the promise theory describes policy governed services, in a framework of completely autonomous agents, which assist one another by voluntary cooperation alone.

[29] Promise theory may be viewed as a logical and graph theoretical framework for understanding complex relationships in networks, where many constraints have to be met, which was developed at Oslo University College, by drawing on ideas from several different lines of research conducted there, including policy based management, graph theory, logic and configuration management.

This makes them mathematically interesting as a notion of space, and offers a useful way of modeling physical and virtual information systems.

Promise graph example
An example promise theory diagram illustrating partial ordering of agents by promise.