Equally, the heterogeneous and permutating assemblage of materials, machines and practices which we call the urban implies a global stratum that is locally embedded. If the urban is something that one can work with, intervene into, or become a part of, then it is important to understand its forces and layers and also to understand how it interlaces the global with the local. The urban is a machine. Machines' can be social bodies, industrial complexes, psychological or cultural formations, such as the complex of desires, habits and incentives that create particular forms of collective behaviour in groups of individuals, or the aggregation of materials, instruments, human individuals, lines of communication, rules and conventions that together constitute a factory or administrative institution. These are examples for 'machines' which are assemblages of heterogeneous parts, aggregations which transform forces, articulate and propel their elements, and force them into a continuous state of transformation and becoming.
Machines are multiplicities without unity, they are criss-crossed by multiple lines of forces.
The urban is a machine that connects and disconnects, articulates and disarticulates, frames and releases. It offers the impression that it can be channeled and controled, that it can be ordered and structured. The city is always an attempt at realising this order which, however, is nothing but a temporary manifestations of the urban. Cities are moments or segments of ordering and reterritorialisation in the deterritorialising machinic process of the urban abstract machine. The machine is always productive, as against the 'anti-production' of a fixed structure.