It does not really make sense to separate the acts of initial engagement, assessment and intervention as if they were entirely separate, sequential actions to be applied in strict order.

The realities of clinical work, from the very first acts of engagement, involve multiple (often subtle, almost unconscious) assessments on the part of the KeyWorker as to what is and is not likely to be helpful and acceptable to the young person and the family. Further, we assume that assessment itself is a major intervention in and of itself.

Likewise, in keeping with the cybernetic principles that underpin much systemic thinking, any assessment involves multiple small trial interventions with the feedback from these influencing the subsequent course of the assessment, and the nature of subsequent interventions that ultimately flow from this.

For instance, the KeyWorker may try using a simple cognitive behavioural technique such as scoring symptom severity; partly to get information on the young person's perception of the impact of a symptom, but partly also to determine the extent to which the young person may be amenable to cognitive behavioural approaches at a later date.

Similarly, it is not the case that no Relapse prevention training takes place until a certain (somewhat arbitrary) point has been reached; instead these two phases intersect and overlap, with opportunities for Relapse Prevention work being taken during lucid intervals at the earliest stages, and interventions from the Acute Phase extending into, and potentially beyond, the second phase.

So, acknowledging this fact, the KeyWorker will still need to have a clear RiskAssessment, Formulation and Treatment Aims, and Care Plan which will provide underlying structure and guidance on the question of WhichInterventionWhen.