aim of this report is to explore Six Sigma techniques that can be applied in a
hospital. It will cover how to approach implementation and the impact to
1.2 Six Sigma
Sigma is a powerful tool used to drive wide spread improvement across an
organisation, encompassing a range of different tools and techniques. Six Sigma
originates from the manufacturing sector. The aim is to reduce defects, and
in-turn improve financial outputs and customer satisfaction. This philosophy
can be adapted to any industry. A very important aspect to understand when
considering Six Sigma applications is that it is an on-going evolution of
methods and approaches, which fluidly links with other quality techniques for
optimised business outputs. In specific cases the most effective tools to be
applied in order to identify inefficiencies in a process and to optimise these
with a customer focus may vary.
for a hospital customer
about quality for the customer it is important to consider both patients and
hospital staff. Whilst the patient is the ultimate customer, the satisfaction
of the hospital staff is closely linked to the quality of the care that they
receive. Unlike in other industries where cost to the customer is a key element
of satisfaction, cost is rarely a factor for patients in the UK. This is
because most patients are funded by the NHS or by private medical insurance. As
a result there is a greater emphasis on quality of care, in understanding
satisfaction. Quality covers experiences across a patient’s full journey:
before and during hospital admission, and in recovery following discharge.
Customer satisfaction metrics encompass improvements to health, time through
hospital stages, expectations management, and general experience (e.g. attentiveness
of staff, cleanliness of environment and food).
improvement in Hospital
flow through the hospital is a complex process involving multiple different
divisions. Each step in the process is vulnerable to introducing inefficiencies
into the system. There are two different patient
flow journeys to consider. One is emergency either via ambulance or via A
department, and the second is planned care, known as elective. These two
patient journeys are closely linked as they commonly use the same resources, in
particular beds and operating facilities, and require input from overlapping
health care professionals. This means when making improvements in one patient journey,
the other must also be considered to ensure no secondary negative side
effects. Sub-processes can be
considered with respect to time including time to: arrive, assessment,
treatment, departure or admission, assignment of bed/ward, and discharge 1. Hospital
capacity and occupancy impact patient flow. As a result, delays, particularly without
appropriate explanation, reduce customer satisfaction.
tools and techniques
Sigma is an on-going development always seeking new techniques for quality, and
evolving methodologies and approaches for improvement. This
means individuals in charge of a Six Sigma project should regularly review the latest
materials, as well as ensuring there are incremental improvements. Significant
long-term improvement takes time and requires a commitment to the project that
is sustained even during initial phases, where benefits are yet to be seen. The
Six Sigma framework DMAIC (Define, Measure, Analyse, Improve, Control) is used
to systematically work through the goals, objectives and performance of a
business to analyse and improve processes.
begin the project must be defined. Through understanding the vision, mission
and values of the organisation, the strategic objectives can be outlined. Using
company statements ensures that the project resonates with the company strategy
2. The scope, schedule, deliverables and team approach can consequently be
determined by understanding how the process works and who it involves and
affects. Once this is realised the most appropriate methods can be established.
voice of the customer (VoC) should also be considered when determining the best
methods. This will combine both feedback about the experience and expectation
of the service, from data collected in surveys, questionnaires and focus groups.
Understanding the VoC in a service industry is slightly more complicated than
in the manufacturing industry, as it is extremely subjective and can vary
significantly on a case-by-case basis. Looking specifically at the hospital,
raises even more problems as expectations can be drastically outside reality.
For many people, healthcare is not a service frequently used, which means there
is nothing to compare the quality of the service provision to. Recording the
VoC is also difficult, as often patients are not in the right state or cannot
see the bigger picture in order to accurately complete surveys or
questionnaires. The Friends & Family
test is used to record a more objective view, as the patient rates if they
would recommend the hospital to friends 3. Patients may have negative
feelings about being at hospital, but this question allows them to recognise if
it was still good treatment they received.
tools are most appropriate as it encompasses perspectives from the organisation
and hospital users.
the objectives have been outlined and processes understood, techniques to
measure these factors must be applied for statistical analysis. The processes measured can be chosen to help
translate the VOC and will aid development of explicit targets and outputs.
Six Sigma goal is to reach a level of 3.4 defects per million opportunities. In
the manufacturing industry this quantified target is easy to understand and aim
for, where defects can be identified as waste material, rework, design flaws
etc. which all have direct links to cost waste. Poor quality operation incurs additional
costs of staff time, operational cost and additional material for example.
target is more difficult to interpret in the context of a hospital. When
dealing with someone’s health, prescribing the wrong drugs or performing an
operation not to protocol can result in death. In healthcare, there should be
no tolerance for poor quality as it risks a life. Thorough understanding of the
problems, customer requirements and expectations in the healthcare sector will
empower stakeholders to take action to a positive change with reduced process
are an essential tool for this step to determine when variation is due to
common-cause or special-cause variation. This tool is preferred as it can
easily identify variations due to different timings, for example a slower time
to be assessed on the weekend as there is higher demand relative to the number
of hospital staff that are working.
SPC (statistical processes control)
to measure sub-processes of patient flow will allow hospitals to understand
where there is variation and where to intervene to achieve an overall
improvement. The hospital should include benchmarking
in their SPC analysis, to allow them to compare their performance with others.
This encourages knowledge sharing and questioning between hospitals which can
help develop guidance on how to better improve sub-processes.
charts fit data in relation to three lines, the mean line which is positioned
between the upper control limit and lower control limit, UCL and LCL
respectively. These limits are set as a function of the data and can be
identified through past data and by defining common cause variated data points.
get the most out of SPC, rules must be followed to assist the analysis of data
to identify is there is special-cause variation in the process 4.
point outside of the control limits.
than 6 points consecutively above or below the mean line.
trend of 6 points, i.e. continual increase or decrease of points
than 2/3rds of points fall inside of the middle third zone around the mean
one of these rules has been broken, the special-cause can be explored by
finding where on the timeline it is occurred. Investigating factors such as day,
time, who was on shift etc. will enable the problem to be identified. It can be
eradicated from the process.
example of use for an SPC chart with benchmarking would be for the measurement
of average time waited for assessment. The process to assessment is important
as a patients’ health and condition can
rapidly escalate with delay, which may result in immediate complications or
additional needs down the line. It is also an important contributor to patient
satisfaction and experience, as a being seen by a doctor quickly reduces
concerns and ensures patients that their needs have been noted.
there will be variation through-out and across many processes within this
project. Pareto analysis of the
results from SPC chart measures will highlight what focusses have the potential
for the most improvement. Pareto’s Principle states that “80% of the effects
comes from 20% of the causes” 5. Figure 1 below shows an example of how
Pareto analysis has been applied for analysis of a company’s website. This is
used as reference to understand how to identify what causes to focus on.
Figure 1: Website example using pareto analysis 6.
shown on the diagram, the bar chart indicates the count error for each cause of
failure. The red line is associated with the right-hand-side vertical axis
showing the cumulative percentage of total errors. By drawing a horizontal line
at 80% to the cumulative percentage line and finding where it intercepts then
shows the most important causes on the left-hand-side on the horizontal axis.
using ‘the 5 whys’ reveals different layers of the problem until you reach the
root, as you continuously ask why (5 as a rule of thumb). It ensures that the true
cause is tackled and not symptoms of the problem. This tool is reliant on that
the right questions are asked and answers aren’t assumed or rushed to
conclusions. Using the sub-processes of patient flow previously mentioned, an
example can be drawn from delay to initial assessment. Why:
consultant was available. Why?
appropriate consultant was arranging discharge for another patient. Why?
plans had been set into place. Why?
responsibility does not directly fall to anyone. Why?
this case setting up a process by which a plan for an inpatient’s discharge is
initiated from the beginning will reduce the strain on consultant’s work load.
Using root-cause analysis is also beneficial as it will uncover potential
causes associated with multiple problems, emphasizing the influence on total
project improvement that could be experienced.
stage takes everything that has been learnt from the previous steps, bringing
it together to brainstorm different solutions to develop, test, review and
implement to address the outlined problem statements and root-causes. Brainstorming is a useful tool to
create new ideas to resolve process problems. However, it is only effective if
carried out in a judgment-free, creative environment, where everyone
participating feels comfortable to suggest ideas, without it turning into a
debate but instead building and reflecting off each other 7.
PDSA (plan, do, study, act)
is a cyclic framework which is proven very useful to test out changes on a
small scale before total implementation. It is important to remember from the
define stage the mission, vision and value statement as this should resonate
through the solution strategies. The first task is to record all actions that
input into the change solution. Then review the impact, by running the test,
noting all results, how it compared to predictions and what can be learned. It
is important that the solutions have measurable outputs or benefits so that we
can have continuous learning and identify the success of the plan. From this,
amendments can be made to the next cycle and eventually lead to full
implementation. This should be repeated for each solution identified in the analyse
The Kano Model
shown in figure 1, can be used to illustrate requirements and expectations. The
Kano Model has limited benefits as it does not give any suggestions on ideas
that would lead to improvement. A customer, patient, will expect to be taken
care of and given appropriate treatment. It is difficult to outline excitement
qualities in healthcare, as it can coincide with expectations. However, using
the model can be useful in this stage, to ensure that all the spoken, and
un-spoken requirements are still accounted for whilst pursuing a new strategy,
which introduces excitement qualities.
Figure 1: The Kano Model 8
a control process in place is crucial in ensuring every step of improvement and
success is maintained and to lead to an ethos of continual improvement and
learning. Using tools mentioned previously, such as SPC, on an ongoing basis will
mean that variation can continually be checked and reduced. Continual learning
by using PDSA is key, and leads into SDSA which stands for ‘standardise, do, study, act’. This
emphasises an important concept, that changes introduced become normal and
widespread throughout the hospital and can be shared with other hospitals. Six
Sigma application should not end here but be a continuous cycle through the
DMAIC framework. Updating as the VoC, and company statements change and
developing as excitement attributes transition to performance attributes.
Expected Improvements and Mechanism of Impact
hospitals in the UK are mainly publicly funded and receive most of their income
based on their activity. A tariff system is in place which mean there are set
prices for different types of appointment and procedure. This means that the
dynamics for increasing financial gain are different to many other industries,
for example manufacturing. Across the country, hospitals are facing significant
financial pressures which result in restrictions being placed on the
organisations by the regulators and commissioners. By managing costs more
effectively hospitals can improve their efficiency avoiding regulatory
restrictions and ensuring funds are spent in a way that benefits patients and
the scope of the project is very important to ensure that the task is
manageable and reflects the needs of everyone involved. As customer
satisfaction is heavily influenced by actions of staff and the quality of the
intervention from arrival to discharge, the processes in the hospital must run
hospital has a duty of delivering high quality healthcare, available to
everyone. Core NHS values include demonstrating compassion, acting with
integrity, listening and supporting other and striving for excellence 9. A
prominent issue preventing the provision of this is slow patient flow. Starting
at the ‘end of the line’, prolonged patient stay can be introduced by delayed
discharge. This occurs when a patient cannot be discharged from hospital
despite being medically fit, which means they continue to use the hospital bed
for longer, preventing other patients from being admitted into the hospital
ward. Whilst multiple individuals across teams in the hospital work to find a
solution, other patients are disrupted. Planned surgeries are commonly
cancelled if there are not enough beds available for recovery post procedure.
These ‘bed blockers’ also have a significant impact on A&E waiting times,
where patients with significant needs may have extended waiting times as there
is a limit in beds for them to be admitted to. Not only can each process
introduce delay but can severely influence the waiting times in the other
processes. The large interdependencies compounds the inefficiencies brought
into the system.
healthcare, given there are so many different services being run, total
efficiency is hard to achieve. SPC is essential in measuring process variation
and enables analysis to identify special-cause variation. The human element of
the processes challenges the extent of what can be achieved but efforts to
eliminate special-cause and reduce common-cause variation can improve
efficiency. If inefficiencies in a hospital processes are reduced, this will
allow better allocation of staffing, so that there are enough to cope with the
demand, but not too many that morale drops because staff members are
charts recording the following data would be recommended, for patients arriving
Time to assessment
Time to admission
Number of patients admitted
Time to assignment of bed and ward
Time to treatment
Time to discharge
Staff sickness days
Satisfaction scores from friends &
similar set of charts could also be created for planned procedures. In addition
to the metrics above, with planned procedures it will be important to measure
the number of cancellations (where warning is given) and ‘Did not Attend’
(where no warning is given) rates.
charts of the suggested data would provide an insight into where problems arise
in patient flow, and promote progress towards the NHS goal of a 4-hour
performance window in A&E 10. Charts vii and viii don’t directly
influence patient flow, but are important aspects in providing care in a
hospital, relating to satisfaction of staff and patients. A happier work force,
with new strategies for more effective processes, reducing delays should result
in happier patients and families.
For example, creating a
more efficient process for a patient’s journey, by minimising a patient’s time
through hospital. This will have significant benefits for a patient and reduces
costs for the hospital. The hospital incurs additional costs for every
additional day that a patient spends in hospital, without receiving any
additional income given the tariff system used by the NHS 11. Furthermore,
when a patient spends more days in a hospital that is medically fit it prevents
other patients with higher needs, who would bring additional income for the
hospital, from using the bed. This is commonly referred to as ‘bed blocking’ 12
and causes huge pressures in winter months when demand in A departments
is particularly high.
Six Sigma techniques with a systematic approach through the DMAIC framework is
very important. Picking and choosing only a few of the tools discussed in
Section 2 will not reap maximum benefits as important elements in understanding
what the problem is, why it is happening, how to solve it, and how to keep the
customer at the focus could be lost.
of all these processes requires training. Communication between patients,
hospital employees, stakeholder, and Six Sigma Champions must be clear and
coherent. It is important that the use of technical jargon is avoided and if
necessary explained plainly. This is because if made too complicated the
concepts, and new strategies will be totally discarded. Continual training is
essential to ensure that the hospital is always pushing for improvement.
is often a pre-conception that improved quality costs more, but if managed
correctly, quality improvement should drive cost benefits. This highlights an
important aspect in introducing Six Sigma that training should not just cover
how to implement the tools and instructions of new strategies for improvement,
but also education into the broad plan of the problems, and the impact change
will have. For example, if a patient receives high quality intervention and treatment,
the chances of emergency readmission, or the need for follow up appointments is
reduced and hence there is less demand and cost associated to that patient 13.
Some processes have time pressures associated with them, it is important that
staff education in understanding that rushing and undercutting, will not
generate improvements. For example, rushing initial assessments, so that more
patients can be seen quicker, can introduce serious complications if misdiagnosed,
and increase costs on wrong treatments or prescriptions.
From this report, a
systematic approach of tools and techniques has been discussed, identifying the
DMAIC framework as essential. Defining the scope through organisational goals,
as well as keeping the VoC as a focus, creates targets for development and
identifies what factors are not meeting expectations. SPC is a vital tool in
measuring process variation, highlighting inefficiencies throughout the
hospital. It is a tool which can easily be analysed to help remove/reduce
variation. Pareto and root-cause analysis help to find the underlying problems,
which can be eradicated through brainstorm new strategies. Ensuring this
process is continuous and maintained is critical to keep a continuous improvement
system. Achieving less variation in a process, means that it will be more
effective and efficient and through a better utilisation of staff and
materials, a better healthcare environment will be provided for patients. This
will lead to a much higher customer satisfaction rating and better care
intervention. Reduced time through patient journey will decrease strain and
drive costs down, achieving financial gains.
1 Digital.nhs.uk. (2018). Accident and Emergency, Patient Journey
– 2007-08, A and E HES data, Further analysis, Experimental statistics.
online Available at: http://digital.nhs.uk/catalogue/PUB02547 Accessed 16
2 Knowles, G. (2011). Six Sigma. bookboon.com.
3 Nhs.uk. (2018). NHS Friends and Family Test –
Patient feedback – NHS Choices. online Available at:
Accessed 16 Jan. 2018.
4 West of England Academic Health Science Network.
(2018). Statistical Process Control (SPC) Charts – West of England
Academic Health Science Network. online Available at:
Accessed 16 Jan. 2018.
5 MURALIDHARAN, K. (2016). Six Sigma For
Organizational Excellence. S.l.: SPRINGER.
6 Project Smart. (2018). Pareto Analysis Step by
Step. online Available at:
https://www.projectsmart.co.uk/pareto-analysis-step-by-step.php Accessed 16
7 Pierobon.org. (2018). The Four Rules of Brainstorming.
online Available at: http://www.pierobon.org/npd/brainst/fourrule.htm
Accessed 16 Jan. 2018.
8 Mindtools.com. (2018). Kano Model Analysis:
Delivering Products That Will Delight. online Available at:
https://www.mindtools.com/pages/article/newCT_97.htm Accessed 16 Jan. 2018.
9 Northdevonhealth.nhs.uk. (2018). Smartcare «
Northern Devon Healthcare NHS Trust NDHT. online Available at:
http://www.northdevonhealth.nhs.uk/smartcare/ Accessed 16 Jan. 2018.
10 Uhcw.nhs.uk. (2018). A 4 Hour Wait.
online Available at:
Accessed 16 Jan. 2018.
11 England, N. (2018). NHS England » NHS payment
system. online England.nhs.uk. Available at:
https://www.england.nhs.uk/resources/pay-syst Accessed 17 Jan. 2018.
12 Laura Donnelly and Reporters, T. (2018). NHS
bed-blocking rises 42% in a year, new figures show. online The Telegraph.
Accessed 17 Jan. 2018.
13 Gponline.com. (2018). Readmissions within 30 days
cost the NHS £1.6bn a year | GPonline. online Available at: https://www.gponline.com/readmissions-within-30-days-cost-nhs-16bn-year/article/1011933
Accessed 17 Jan. 2018.