Each natural event that affects urban regions reveals the limitations of present risk management strategies and shows the prevailing importance of technical systems before, during and after each crisis. The response of such systems to risk can be discussed in terms of resilience. Resilience is a concept that applies generally to systems, and concerns the capacity to absorb a disturbance and to return to a viable state. In the context of urban technical systems, one element of a resilience strategy is to analyse the technical constraints that apply to the design, management and adoption of technical systems. This paper presents the design of a conceptual model presenting the various possible resilience strategies applied to urban technical systems. This conceptual resilience model for technical systems is based on the identification of four complementary types of resilience: i. cognitive resilience, linked to knowledge and culture; ii. functional resilience, representing the capacity of a technical system to protect itself from major damage while continuing to provide at least the services needed by critical infrastructure; functional resilience of technical services seeking intrinsically to increase their own resilience; iii. correlative resilience that characterises the relationship between service demand and the capacity of the technical system to respond. It is a matter of adapting demand to technical system capacity: decreasing demand enables a system to remain in operation and to recover more quickly. Internal system organisation as well as links between technical systems and other regions may also be a factor in the resilience of technical systems. iv. Organisational resilience expresses the capacity to mobilise an area much wider than the one affected.