The problem with demand and capacity is that it is mostly misunderstood
Blog 3 in the Quality Matters: From Insight to Impact series
Quality Improvement (QI) is critical to delivering on the NHS Plan. This series of articles from Associate Directors, Ian and Laura, provides a personal and practical insight into how QI is needed more than ever.
Veran Patel, Director, Health & Social Care
What we see and hear
A medical director brought a request to the management team seeking funding to increase medical staffing in a particular service from four to seven. “Why seven?”, I asked, to which the response was, “four is clearly not enough as we have a backlog, and seven is what the Trust down the road has”. The management team agreed the funding.
A commercial director leading a response to a tender said, “We need 3 nurse wte in the team”. I asked, “why 3?” which garnered the response, “that is what the funding allows for”. That is what went into the bid, the bid was successful and soon after go-live, people said there was insufficient nursing capacity.
A chief executive asked how many referrals we received a year from a particular locality. I said, “2100” and the performance director said, “9000”. The chief executive was irritated. It was 2100.
An operational manager said, “we have the capacity to do 18 contacts a week per wte”. I said, “over the last 12 months the average has been 10 and there is a backlog”. The manager said, “18 is what is in the contract”.
An operations director advised that cultural issues in a call-handling team meant calls were not being answered. We did not discover any cultural issues but did work out there was a near 50% shortfall in capacity, and in any event, capacity was not rostered to align with peaks and troughs of calls. Oh!
A service manager said, “poor admin booking processes mean we often miss a 2-week target for emergency eye appointments”. I asked, “how many emergency appointment slots are there per week and how many referrals?”. The manager responded, “12 slots per week but I don’t know the number of referrals”. We asked the admin manager how many emergency referrals they get per week, and they replied, “it varies, around 25 to 30”. The admin manager was correct and each week they contacted up to 20 patients by phone to re-schedule routine appointments to fit in the emergency ones; a local booking rule ensured the same patient was not re-scheduled more than 3 times.
We asked a cancer manager, “what is the demand into the service?” to which they responded with their 62 day RTT performance data, current number of patients not treated within 100 days and current number of patients waiting for their first appointment. They then went on to explain the waiting list initiative that would fix all of that – it didn’t.
An endoscopy manager said they were tasked with: increasing the number of procedures carried out by the Trust; reducing the number of procedures referred out to the private sector; hitting the 6-week target. We asked, “so, how many endoscopies are required, how many do you do, how many are farmed out to the private sector, and how many of all of those achieve the 6 weeks target” to which the response was, “we don’t know, it is really hard to get that information from our systems”.
And finally, a workforce director came to me one day and said, “can I borrow 2 of your team for a week to help manually transfer paper records to ESR?”. I responded, “why two people and why one week?”. They said, “I knew you would say that! Please don’t make me work it out!”. We did it together and discovered that it would take 2 staff about 3 months to do the task.
So, what is going on?
Many things possibly, including:
- People don’t have access to the data that would help them
- They have the data but are scared by the maths
- Rules of thumb are easier and to many, they sound like evidence
- People believe backlog is proof of insufficient resource
- No one asks people to do work our demand and capacity, no one shows them how
- It isn’t considered important or worthwhile
Our own guess is that people (perhaps the NHS generally) have sort of missed a crucial point in about just what demand and capacity is, and why it is vital to understand it.
The crucial point!
Demand is not really about how many referrals, or whatever you get – DEMAND is about calculating how much WORK those referrals generate.
Capacity is not really about how many staff, beds or clinics you have – CAPACITY is about how much WORK those resources can fulfil.
We have to convert it all into the CURRENCY of WORK.
So, how do you calculate the work?
At one level it is pretty simple, and if you were running a burger stall you would probably do this without thinking. Let us use that as an example. First, we observe (literally) and time all the work to order, pay, make and serve one burger, together with the equipment and resources required.
Work time to make a burger 2 minutes
Work time to take an order 30 sec
Work time to process payment 30 sec
Cooking time 8 minutes
Second, we divide that by how often we get an order for a burger. This is called Takt Time and in this example it is 4 minutes. The result tells us how many we need of something to sustain the operation.
Number of people making burgers: 2 / 4 = 0.5 people
Number of people taking orders: 0.5 / 4 = 0.125 people
Number of people taking payment: 0.5 / 4 = 0.125 people
Number of burgers being cooked at one time: 8 / 4 = 2 burgers on a grill
So, one person will be 75% utilised if they undertake all the work, and we only need a grill capable of cooking 2 burgers at a time. If one day we park outside a football ground and realise we get an order every 30 seconds, we can quickly work out that to meet this new demand we will need 6 staff (4 x chefs, 1 x orders, 1 x payment) and a grill capable of cooking 16 burgers.
And is it as simple as that then?
Mostly. If we know how long each element of work takes (known as its cycle time) and, typically from system data, how often we get a piece of work to do (takt) then the maths of it is the same.
What can make it more complicated is:
- If there is a lot of work being done, by a lot of different people, over a long time span. You need to capture all work, and this takes time. For simple processes it takes much less time.
- Not all work is done in the same way. We account for this in how we calculate cycle times. Standardised processes will help reduce this variation and perhaps improve quality.
- Different needs of patients might mean the detail and duration of the task varies. Again, we can account for this in cycle time calculations. If the time is very different and number of patients significant, we can consider sub-pathways to optimise flow. Pareto charts are a good way of bringing this to life.
- Demand does not enter our system like the drum beat of takt time. At different times (of day, week, month, year) demand and takt time might vary. Demand varies less than many believe but we can still account for it. In ED takt time varies by hour but is very predictable – we can calculate required capacity by hour to best align it to demand.
- People do not just do this work. Many staff operate across a number of processes and there is other ‘stuff’ to do. What we capture here is only the resource to perform this process / service and let us say that comes to 20 wte. When we look at what time staff spend on other work and non-work activity, we might find it comes to say, 50% of time. So, we will need 40 wte to sustain the 20 wte capacity we need to operate the service at any time.
Anything to add?
Yes, something really important and beneficial. As well as gaining a far better understanding of demand and capacity, the added benefit of working in this way is that it forces you to observe and understand all the processes and ways of working our staff undertake. You gain great insight into the struggle of staff to perform the work required of them and you will unearth no end of improvement opportunities. Also, spending such time with staff is brilliant for engagement and building relationships – something that will help you empower staff to exploit those improvement opportunities. It might also make you question any premise that demand outstrips capacity – the way we work now does, the way we could work is altogether different.
And a word of caution. No matter how convenient it would be, do not believe for one second there is a short cut to observing the work to understand it: staff self-recording time on task; estimating time / task in ‘process-mapping’; extracting time stamps from IT systems; even deploying electronic trackers – we have seen it all and in every example the results have been wildly inaccurate.
Laura Woodward and Ian Railton are Quality Improvement (QI) experts and are Associate Directors at TIAA. This series of fortnightly blogs are their insights into a long career and successful track record of working with healthcare organisation to improve productivity and better outcomes for patients.
Click here to read the first blog in the series – Quality Matters: From Insight to Impact; Before solving a problem, you must first understand it
Click here to read the second blog in the series – Quality Matters: From Insight to Impact – 7 Traits of an Improver