Bottleneck Theory

Internal Waits to Specific Partnership: can be waits for internal specific assessments or interventions using advanced skills and used to be a common problem in traditional CAMHS models and still can be in CAPA too. However CAPA gives you tools to solve or at least understand this problem. It can be best understood by considering bottlenecks from the point of view of demand and capacity theory.

So here is the bottleneck theory bit…

A bottleneck is where there is a demand and capacity imbalance. The evidence of one is a wait- ing list for something. It only appears when the demand exceeds the capacity. It can be because demand has risen or capacity fallen. This may

be in the past and the extra referrals say are still sitting in the waiting list but the current demand and capacity balance is matched i.e. the list is not growing. Or the imbalance is in the present and the waiting list growing.

CAMHS example: A CAMHS team might have no waiting list and be seeing all the referred families. However, a maternity leave may add roughly 50 patients to a waiting list for a particular skill because of the large effect of staff loss on small teams and after the staff member and the team returns to demand/ capacity balance the unseen 50 cases are still sitting on the waiting list.

OK here is a small bottleneck quiz...

Question 1: in a passport office there are 4 steps that take different lengths of time.

  1. 1 hour then
  2. 2 hours then
  3. 1 hour then
  4. 1 hour and 30 minutes

If there is one staff member on each step then

  1. Ahead of which step will the bottleneck be?
  2. Which member of staff is going to be sitting about doing nothing most often?
  3. How long will it take?

Question 2: NOW you have one additional member of staff to deploy…

  1. Where would you put them?
  2. Where will the queue be now?
  3. How long will it now take?
  4. Where would the least useful place to put them be and why?!!

Soundbite statement

The only ways of changing a bottleneck are REDUCING demand or INCREASING capacity. For waits to Specific Partnership interventions / assessments you will need to either reduce the demand (i.e. what is coming into the bottleneck) or increase the capacity (i.e. widen the bottle- neck) or both.

Practice Point: when there is a wait or bottleneck most people feel that the solution is to increase the resource after the bottleneck i.e. more of whatever it is. However, a more effective solution is to increase the resource BEFORE the bottleneck. This is often cheaper, simpler and faster. We may not need more psychiatrists if we have more staff able to do a good mental state assessment reserving the psychiatrists for complexity.