The Packing of Fruit

So what happens in a clinical service if we don’t segment the work? Let’s work through these ideas by packing fruit into crates!

One big crate

Imagine we have one large fruit crate and we want to fill it with various types of fruit. This is fairly easy!

However it is hard to know quite how much fruit we can put in this crate unless we know the size of the crate (obviously) and the size and number of the different types of fruit.

Four small crates

OK to make it easier let’s divide this big crate into 4 smaller crates of equal size...

So now we have our pile of different fruits and 4 fruit crates. What now?

Average Sized Fruit

Average fruit

We start by grouping our fruit according to size. We have apples and oranges - different but the same size, an average size. We will have two crates allocated to these average sized fruit as most of the fruit we have is average sized.

Now because we know the size of the fruit and the size of the crates we can say quite accurately how many average sized fruit we can fit into the crates. In CAPA these averaged sized fruit are those clients seen in Core Partnership.

Other fruit


You need to allocate another crate to your larger fruits (such as melons). Again this is so we can know how many melons we can fit in. In CAPA this group is Specific Partnership. Specific as it’s not average sized. You need to identify a specific crate for these melons and not accidentally mix them with apples or oranges!

Each of your specific crates will hold fewer, big fruit. What’s the benefit of this?

Well, if we know that we need to store a certain number of apples, oranges and melons we can now calculate how many crates will need to allocate to the averaged size fruit and to the larger (i.e. non average sized) melons.

Are there any other segmentations that are useful?


Well, we might have other different sized fruit: pumpkins (and yes we know they aren’t fruit!). They are even bigger than melons.

So it’s a lot easier if we segment the melons and the pumpkins into different crates. In CAPA language this is another Specific Partnership segment or workstream.

Why didn’t we just put the pumpkins in with the melons?

Well although they were of a similar order of size – big – they were different enough that we couldn’t calculate how much space we would need to pack all the melons and pumpkins in unless we knew the specific ratio of pumpkins to melons. We may also have decided they needed different tools (skills) to prepare them and so separation is helpful.

Clinical explanation

So to translate this metaphor into clinical practice… all these pieces of fruit have helped us describe how and why we segment our clinical time for different reasons. The biggest number of crates was used for averaged sized fruit (we had the most of it) – so this is Core Partnership work for interventions of an average duration. Then there were one reason for specific segmentation: duration (longer or shorter = extended or brief).

To recap: the biggest reason for different segments is HOW LONG DOES THE INTERVENTION TAKE?

Segmentation: master class

In the above examples the size of the crates was fixed. However in a clinical service the size of the core and different specific partnership “crates” needs to vary depending on the number of fruit that are arriving at the service. And how much each clinician’s work is segmented into those streams depends on the clinical skills mix you have AND the demand for that skill mix.


These are the ideas behind why segmentation is useful in working out how much capacity we have in any particular work stream.

For the details on the actual maths see Implementation on this site