Six Sigma Service at the Speed of Lean
Why Services are Special
The Ubiquity of Services:
We encounter services everywhere, from health care, hospitality,
and transport to government, retail and financial services. Even
within manufacturing organisations, a significant portion of the
activities are service related.
The Visibility Challenge:
While services are everywhere, the steps involved in the
processes are difficult to visualise. For instance where on a
production line, you can directly see the amount of work in
process, or measure lead time by following a work piece from one
end of the process to the other, the same is not always possible
with services. An observer would be hard pressed to say how much
work in process a data analyst working mainly with his computer
has.
The Prevalence of Waste:
Services are generally prone to waste. A major reason is that
there is usually too much work in process. These may be sales
orders, reports on a desk awaiting review or approval, emails to
be responded to, or customers waiting to be served. Up to 90% of
the time work spends in process it is just waiting.
Substantial work in process makes services slow, which drives up
costs and makes them prone to poor quality.
Other common wastes include people moving around chasing
information, documents looping back and forth where items are
being clarified, interruptions etc.
The High Variation in Demand:
Services, particularly those dealing directly with customers
generally face highly variable demand. Consider the case of
hotel clerks checking in guests. There will be periods of low
activity and at other times many guests will be in queue,
waiting to be checked in. The situation is similar in a
restaurant or shopping mall. The impact of such variation on WIP
is significant.
The Relative Absence of Hard Data:
Service personnel are not accustomed to the same level of rigor
in collecting and analysing data as their manufacturing
counterparts.
Applying Lean Six Sigma to Improve Services
Define Improvement Targets on the Basis of VOC: Use reactive and
proactive means to listen to the voice of the customer.
Reactive methods are those where the customer takes the
initiative through complaints, compliments, enquiries, web page
hits, emails and the like. Reactive methods are good at
detecting service weaknesses as customers will most likely
contact you when they have problems.
Proactive methods are those where you take the initiative to
gather customer information and include surveys, questionnaires,
focus groups etc. This information ensures that improvement
targets you set are based on customer needs.
Make the Relevant Processes Visible:
The relevant processes target for improvement should be observed
and mapped. This is not very easy to do, considering the nature
of services. However with the cooperation and involvement of
stakeholders and process operators, a lot can be achieved.
For each activity in the process, information required in
creating the value stream map include estimated cost per
activity, process time, queue time, change over time, demand
rate, complexity (number of different services processed at the
activity), uptime and defects/rework. This data should be
collected based on at least one week of observation. The
resulting map is known as a complexity value stream map.
Determine the Time Traps (to prioritise projects):
Using a complexity value stream mapping software, the activities
which contribute most to non-value added time will be visible.
These are the time traps. Following from the Pareto law, usually
80% of the non-value added time can be accounted for by 20% of
the activities.
Analyse the Time Traps to Determine their Causes:
A further output from the complexity value stream mapping
software is the cost driver analysis. This specifies whether the
source of the major time traps are primarily quality related,
making them amenable to Six Sigma tools, operations related,
which can be taken care of by Lean tools or complexity related
which requires a streamlining or optimisation of the variety of
service offerings.
Apply Appropriate Tools to Improve the Process:
The foregoing analysis having already pointed out the direction
of improvement efforts, it is now left to apply lean methods to
reduce setup time, reduce work in process or increase completion
rates and six sigma methods to reduce the defects.
Huge opportunities translating to significant cost and time
savings, along with quality improvements, exist in many service
operations where typical process efficiencies are below 10% as
against world class levels of 25-50%.