Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
www.makewayglobal.com © MakeWay 2019 [v4.1]
Lean Six Sigma
Green Belt
Training
Pre-Course Reading Material
Powered by:
- 1 - www.makewayglobal.com © MakeWay 2019 [v4.1]
Getting prepared for your training…
Thank you for choosing your training with us. We have created these notes to get you started
on your journey into Lean Six Sigma.
Please ensure that you read through this material thoroughly. This is a very intensive
course, so this is a head-start that will be of tremendous benefit to you. It will certainly help
in your understanding of the topics taught in the classroom.
This material is appropriate for those taking the Lean Six Sigma Yellow Belt and/or the Green
Belt course. This Green Belt course is planned to be of practical use, rather than just
academics; so, we have focused the course into a single block of five days.
I. PREPARING FOR THE COURSE
We suggest that you bring everything you need to study with you on the first day; this will
typically include:
• Pens / Pencils / Highlighters / Page Tabs / Simple Calculator / Ruler etc.
Arrive on time: We start promptly and the intensive nature of the course means that if you
miss something you may not have the time to catch up. Additionally, when delegates arrive
late it disrupts the flow of the class and is distracting for the other students as well as the
instructor. Please make sure you are in the class on time, both at the start of the day and
when returning after breaks. Our courses start at 09:00 (or as advised, otherwise) promptly
on the first day. Please be on the premises by 08:30 (or as advised, otherwise) so that you
have time to get yourself settled in.
Additional Support: If you feel that you need additional support on the course, please
contact our team before the course so that your needs can be assessed.
Pre-course preparation
We suggest that the following short preparation will optimise your time on the course:
1. Study the notes in the next section
2. Plan your week to minimise distractions and make sure you have everything you need
ready for the start of the course.
Evening Work: The training is based around the assumption that you will be able to spend
between 1-2 hours each evening reviewing the topics covered on the course, performing
additional research and preparing for the exams. Please make sure there is time in your
schedule to accommodate this.
- 2 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
II. INTRODUCTION TO LEAN SIX SIGMA – PRE-COURSE NOTES
Lean Six Sigma is a process efficiency methodology, which is based on a culture of
continuous improvement. These notes have been prepared as an introduction to aspects of
the body of knowledge required for the Yellow Belt certification.
1.0 WHAT IS LEAN SIX SIGMA?
Lean Six Sigma (L6S) is a fusion between ‘Lean’ and ‘Six Sigma.’ Both Lean and Six Sigma
consist of philosophies, methodologies as well as tools and techniques. Lean and Six Sigma
are highly complementary, so it makes sense to combine them. Together, it is a
methodology devised for a collaborative team effort to improve performance by
systematically eliminating waste (non-value adding activities) and reducing variation.
1.1 The Lean Approach
Lean is a methodology that focuses on improvement in processes through the elimination
of waste (known as ‘muda’ in Japanese, where it originated). It is about delivering value to
the customer, whilst eliminating those parts of the process that contributed no value to the
end result. Basically, Lean, as it is now referred to, was what was created as the Toyota
Production System (TPS) in 1948. It came from the philosophy of “Doing more with less.”
The term, Lean Thinking, is usually used to describe the Lean culture.
“All we are trying to do is reduce the time from order to cash.”
[Taiichi Ohno]
The ultimate goal is to be rid of waste; hence, the need to ensure a perfect value creation
process. Note that Lean is not a cost-cutting exercise. If your focus is to cost costs, one
may end up sacrificing quality, which may invariably lead to losing the customer.
Customer Touch Points:
Imagine a scenario whereby a registered patient goes to a doctor for an annual check-up,
completes the required paperwork and leaves. A few months later, the patient receives a bill
indicating that the health insurance company denied part of the service. The doctor’s office
cannot explain why – they use a third-party billing service and know nothing about the bill.
The billing service cannot help – they just do the paperwork.
After numerous calls to the doctor’s office and insurance company, the patient gives up and
pays the bill. When later asked about a doctor in the area or an insurance company to use,
the patient recommends they look elsewhere.
By measuring each touch point independently you can determine its contribution to the
overall effectiveness as well as more effectively measure the total customer experience. A
Customer
places order
TIME
Delivery process Customer
pays
- 3 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
touch point is any customer interaction or encounter that can influence the customer’s
perception of your product, service, or brand. It is essential to eliminate anything that may
cloud the customer perception.
1.1.1 WASTE (MUDA)
This is anything in the process that does not add value. Muda (無駄) is a Japanese word
meaning “futility; uselessness; wastefulness.” It is worth questioning why it is within the
process. From an end-customer's point of view, value-added work is any activity that
produces goods or provides a service for which a customer is willing to pay; muda is any
constraint or impediment that causes waste to occur. So, the issue is that we discover what
the customer would pay for or the essential elements required to run the business of the
organisation?
Waste elimination is one of the key ways to improve the process and ultimately deliver value
to the customer at a significantly lower and competitive price. To eliminate waste, it is vital
that one understands what it is and where it can be found within the process. For every
muda, there is a strategy to reduce it or eliminate its effect on an organisation so its
process(es) can perform optimally.
1.1.1.1 Muda Categories – Traditional (mainly for manufacturing):
There are seven categories of unproductive manufacturing practices that were identified by
Taiichi Ohno in the TPS in Japan. It is a tool used to categorise muda. Using the
TIMWOOD(S) acronym, these are as follows:
1. Transportation – the movement of products between processes can significantly add to
the time it takes to deliver value. Some of this excessive movement can cause damage
and may result in a loss of quality. Mapping product flows can help to determine a
favourable factory arrangement that reduces the need for much transportation.
2. Inventory (Over) – this is the holding up where work in progress (WIP); a direct result
of overproduction and waiting. Unnecessary inventory tends to hide problems in the
production process and results in such costs as storage, space usage and delayed
identification of problems in the output from another process. Achieving a seamless flow
between processes can significantly eliminate the need for inventory and improve
performance ultimately.
3. Motion – these are related to health and safety issues, which are matters of significant
importance to organisations. This waste is identified in instances of bending, stretching,
walking, lifting, and reaching out for something. The adequate arrangement (with ease
of access) of ‘tools’ and materials will help to reduce the effects of this waste.
4. Waiting – this relates to goods being queued up for action – the fact that they are not
moving or being further processed. To eradicate the waste of waiting, it is valuable to
have processes linked together to enable them fit into one another – the output from a
process feeds in as input to another process.
- 4 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
5. Over-Production – this is the production of goods and services before they are ready
to be taken delivery of or used by the customer (internal or external). Overproduction
leads to excessive lead times, resulting in high costs of inventory and the accompanying
opportunity costs. The counter-activity to overproduction is the Just-in-time (JIT)
technique. The idea in JIT is that only what is needed is to be shipped or accepted by
another actor (or recipient worker) in the process – it is only created in time for their need.
6. Over-Processing – sometimes referred to as using a sledge hammer to crack a nut, this
may be the use of expensive high specification equipment where a simple and least
expensive tool will suffice. The right arrangement of the varying processes with an
attended and adequate allocation of resources make it easier to ensure that the right
tools are employed.
7. Defects (and Rework) – this is a result of churning out defective outputs. These are
quality defects that have a tremendous impact on costs to the organisation. Continuous
process improvement that engages the relevant employees working in the relevant areas
will significantly reduce the impact of waste in an organisation.
8. Skills (unutilised) – this is the waste of human potential (which was not originally part
of the Toyota Production System (TPS). It occurs as a result of the separation of the role
of management from employees. In some organisations, management’s responsibility is
seen within managing and directing (as well as innovation), whilst the employee’s role is
to simply follow orders and execute the work as planned. Eliminating those of the ‘grind’
makes it difficult to improve processes, as those that do the work are usually best placed
to identify problems and develop solutions for them. In manufacturing, this waste can be
seen when employees are poorly trained and unable to effectively operate equipment,
when employees are given the wrong tool for the job, and when employees are not
challenged to come up with ideas to improve the work.
1.1.1.2 Muda Categories – Services (mainly for non-manufacturing):
Those redefined wastes for the service (non-manufacturing) industry, have been referred to
as DOWNTIME with the following descriptions:
1. Defects – this is where output has churned out errors which may result in rework. The
service provided for the customer is defective; it does not meet business or customer
requirements. For example, where the service delivered does not meet the desired
objective or it is not even delivered at all, or to time. Quality in ensuring that the customer
gets what will meet their desires is key – customer requirements must not be ignored.
The ability, not only to define the quality criteria, but to also ensure the adequate quality
process is applied are crucial. It is necessary to get the assessments right so that the
adequate tools and techniques are employed to meet the predefined quality criteria. For
example, clarity in the number of characters that can fit into one field for an online form
being designed – this can lead to missing information.
2. Over-production – this is where one is providing more than what is needed. For
example, this not only includes the production of too many unrequired reports, but the
- 5 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
volume of reviews and approvals along the line. There may also be excessive
documentation or batching of paperwork that is not ready to be acted on.
3. Waiting – this is where the receiving customer is waiting for delivery, service,
information, response etc. There is also the waiting for approval, or even those caused
by equipment downtime. The mitigation here is understanding when the recipient is ready
to receive what is intended and meeting that time. For example, if a design specification
is needed to create a report template, the response should be received at the set time.
4. Non-utilised talent (Skills) – this is the waste of human potential (which was not
originally part of the Toyota Production System (TPS). It occurs as a result of the
separation of the role of management from employees. In some organisations,
management’s responsibility is seen within managing and directing (as well as
innovation), whilst the employee’s role is to simply follow orders and execute the work
as planned. Eliminating those of the ‘grind’ makes it difficult to improve processes, as
those that do the work are usually best placed to identify problems and develop solutions
for them. Within the non-manufacturing sphere, it can include insufficient training, not
asking for employee feedback, and placing employees in positions below their skills and
qualifications.
5. Transportation – the movement of paper rather than the use of electronic transfer. Also,
unnecessary data transfer whereby people are sometimes cc’d on emails that do not
concern them.
6. Inventory – this includes being overstocked or out of stock. In this case there may be
waiting involved – for example, finished deliverables waiting for attention or stock-outs
(queues). This could also be the result of not providing the right thing for the customer
(recipient) or services that may not meet the desired quality specifications.
Communication and clear quality criteria are key to these aspects of avoidance of
incorrect inventory.
7. Motion – this could be where one keeps returning to a queue to check for readiness of
the delivery that is expected but being told to come back later. It is also the non-existence
of a one-stop or a lack of an understanding for efficient practices in the working
environment. To overcome this, processes need to be streamlined and a network of
occurrence clearly mapped. The use of an ergonomic space arrangement is desirable.
Ergonomic refers to the process of designing or arranging workplaces, products and
systems so that they fit the people who need them in their environment.
8. Extra-processing – this is where additional and unnecessary effort is expended more
than once, for example, to record information twice along the process map, such as, re-
entering sales numbers in the financial accounting module of an 1ERP. A planned
integration of the organisation’s processes will eliminate such duplication.
Continuous process improvement that engages the relevant employees working in the
relevant areas will significantly reduce the impact of waste in an organisation. In Lean, a
1 ERP (Enterprise Resource Planning): This is the integrated management of the core aspects of a business process, using software technology. There will be as many defined aspects (or modules) as desired by the business processes. For example, the sales data that are entered in the related sales department feed into the information required by the finance department.
- 6 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
good definition of waste could be “…doing anything that a customer does not need
or perceive as adding value.” This of course raises the question of “Just who is a
customer?”
1.2 THE SIX SIGMA APPROACH
Six Sigma is a data-driven methodology for the elimination of defects in the output churned
out by any process. Created in Motorola in response to the need to improve the quality of
outputs churned out by the production process, its focus is to reduce varied outputs and
thereby avoid customers receiving defective products and services. Waste is seen as
anything that gives rise to unacceptable deviation (defects).
1.2.1 DMAIC (pronounced də-MAY-ick)
Six Sigma created a realistic and quantifiable goal in terms of its target of 3.4 defects per
million operations. It was also accompanied by a methodology, which became a problem-
solving strategy made up of four steps: measure, analyse, improve and control. When GE
launched the approach, they improved upon it and added the define phase.
DMAIC is a good framework for identifying and then removing some of the waste from an
existing process, products and services. There are other frameworks that can be used for
creating new products and services.
Define This phase is concerned with setting up the improvement project and understanding what
needs to be done (the scope). Things to do include:
• forming the improvement team
• identifying where improvement is required in the process
• identifying what the customer desires from this process
• creating the project documentation
Measure Here, the team investigates how the current process is working (‘as is’) and looks for areas
of waste, inefficiencies and high defect levels so that they can develop a picture of where
the process could be improved. Things to do include:
• establishing a data collection plan
• gathering data
Customers will only accept a certain rage of variation.
This customer wants to receive insurance claims in 4 days from the date of submission for a claim, but will accept a variation between 3 to 5 days
Accepta
ble
bolt length
s
6 days
2 days
All processes and systems give out variation. This process delivers based on an agreement of between 3 to 5 days (as represented by the vertical height of the green block)
Variation by process
5 days
3 days
Waste
- 7 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
Analyse The data gathered in the Measure phase is examined to identify areas in which it is practical
to make improvements and to ascertain what the root causes of the wastes are.
Improve In this phase the team decide on the best way to remove or mitigate a root cause and then
the team develops, trials and implements the selected solution, ensuring that appropriate
levels of training and documentation are included.
Control This phase has two main aims:
1. Wrap up the project started in the Define phase
This is basically archiving your project paperwork, working out the potential savings and
debriefing the team.
2. Sustain the change
This is to ensure that the changes introduced in the Improve phase ‘stick’ and putting an
alert mechanism in place to trigger action if the process slips later.
1.3 THE LEAN SIX SIGMA BLEND
The mission statement for L6S, if there were one, is: Producing products which surpass the
expectations of the customer in an efficient and waste-free way.
LEAN SIX SIGMA FUSION – TWO RELATED DISCIPLINES
LEAN SIX SIGMA
Focus Improve system efficiency Improve process effectiveness
- Improve work flow - Reduction of variation in outputs
- Stability of processes
Goal Eliminate waste Reduce defective outputs
Emphasis Deliver value to customer Quality to customer
Some Tools 5S, Muda (Wastes), Flow &
Pull, Kaizen, Kanban, Daily
Stand-Ups, Value-Add
Analysis, Value Stream
Mapping
Critical to Quality, Defects Per Million
Opportunities (DPMO), Failure Mode Effects
Analysis (FMEA), Pareto, Statistics
Some Common Tools Cause and Effect Diagrams, Process Mapping, Standardised Work, Visual
Controls
The two disciplines of Lean and Six Sigma highly complement one another. However, they
do possess their respective philosophies, methodologies as well as tools and techniques.
• The Lean methodology deals with smoothening the process flow and matters of
waste that may affect this flow
• The Six Sigma approach seeks to promote operational and business excellence with
its attention towards eliminating defects in outputs
- 8 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
Lean is… Six Sigma is…
A passionate belief that there is always
a simpler and better way
A never-ending passionate journey to
competitive leadership by satisfying
customer requirements profitably
A continuous drive to identify and
eliminate waste and remove road
blocks to improvement
A statistical measure of a process’s
inherent ability to meet customer
requirements
The empowerment of employees to
drive improvement – no blame culture
Trust is also a key factor
A continuous drive to reduce defects
and variability
The rigorous application of lean tools
and techniques across the whole
organisation
Finding and solving route causes to
failure
Having a rigorous control methodology
Thus, the L6S organisation, is…
➢ a visibly professional and functional workplace…
➢ that delivers high quality outputs and outcomes for its customers…
➢ by motivated managers and teams.
With this methodology, the workforce is better involved in a collaborative manner with
management and thus, empowered to manage change with the guidance of trained mentors.
Six Sigma helps Lean because… Lean helps Six Sigma because…
Lean does not really have a formal
project methodology, whereas Six Sigma
has DMAIC.
Lean provides alternatives to DMAIC for
less complex improvement areas. For
example, Kaizen events can be
performed frequently by everyone.
Lean is very loose, whilst using DMAIC
allows the improvement team to have a
clear set of activities for the Measurement
and Analyse phases.
Lean focuses on waste and end-to-end
flow. Lean defines waste from the
customer’s perspective.
By itself, Six Sigma may take an insular
view, optimising a process to meet a local
target.
Process sigma levels are reached more
rapidly by also considering waste
Lean does not consider the problems with
variation; however, Six Sigma adds
statistical modelling tools to track down
and investigate variation.
Following the common practice of taking the comprehensive toolkit of the Lean philosophy
and injecting it into the more structured and statistically based methodology of Six Sigma, it
gives us a structured and fact-based improvement approach that provides a huge set of
tools and techniques.
- 9 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
1.3.1 Key Principles of Lean Six Sigma
Below are the key principles that guide the operation of the L6S methodology.
1.3.1.1 Focus on the customer; not the business process
This is the crux for serving the needs of the client/customer (i.e. the recipient of an
output/outcome). An organisation that is customer-focused has developed a significant
contributor to the overall success of its business. The effort here is to make everyone within
the business process think of customer satisfaction first.
1.3.1.2 Identify and understand how the work gets done (Value Stream)
Clarity is required for the flow of information and/or materials to provide value to the
customer – what we think is happening may be different from the reality. It is not unusual to
involve an external observer to document the step-by-step work that really gets done.
1.3.1.3 Manage by fact (not by opinion) and reduce variation
It is worthwhile using data to justify one’s decisions. This is the test that is required to gather
data, see what the system is churning out and use these as a basis for managing the process
flow. Collect data before and after the improvement has been carried out.
1.3.1.4 Eliminate waste wherever possible
Once one understands the flow, it is worthwhile to take a further objective look at it. Ask
questions such as: why are we going this loop and not the shorter route? This helps to
manage, improve and smoothen the process flow, to achieve removing non-value-added
activities.
1.3.1.5 Trust and empower your people
It has been said that the best people to understand the workings of a system are those
working directly with it. It is important to involve them and trust their judgment as part of the
decision-making process.
1.3.1.6 Improve systematically
No process is perfect, and should it by any chance be, it cannot stay that way unless it is
constantly on the review radar. So, do not to wait for problems to occur. The question to
consider is: can we do this better? This is the system or culture that must remain in a L6S
enterprise.
1.3.2 The Costs of Lean Six Sigma
Both Lean and Six Sigma are licence- and royalty-free. Anyone is free to use its concepts.
However, there are other costs; prudence suggests the importance of matching these costs
to the presumed benefits.
1.3.2.1 Training and consulting costs
This is where the employees attend a L6S training course, or the training company may
conduct the teaching sessions within the premises of the client’s company. The training
organisation may also provide consultancy services to help embed the learning that was
provided within the actual working environment of the client organisation.
- 10 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
1.3.2.2 Culture change
This is harder to quantify, but L6S is indeed a culture change, particularly, that of trust and
empowerment. The entire organisation, from the top echelon of management right through
to the delivery cadre needs to buy into this culture.
1.3.2.3 Non-productive time
This is the cost of not serving customers. It includes the time spent attending training or
working to eliminate waste.
2.0 PROCESSES
A process can be considered to consist of just three things:
1. Inputs – Various things come into the system (relevant department in the organisation).
In L6S we often refer to inputs as ‘X’s.
2. Outputs – The process takes the inputs and transforms them into something else,
including stuff that the customers want. In L6S, we often refer to the outputs of a process
as ‘Y’s.
3. The last part is really the one in the middle and refers to the transformation itself (this is
also known as an X). It concerns the work or procedures that change what comes in to
what goes out.
The relationship between X’s and Y’s is shown by the formula f(X) = Y, which simply states
that variance in your inputs and how you transform them directly relates to variance in the
outputs. So, for example, if you use a person to work with a new software, the result of the
analysis will differ from that achieved with the old software. If each packer has their own
routine, then the time taken to dispatch an order will also vary proportionately.
Now we have processes sorted, let us get back to Customers!
- 11 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
3.0 WHO IS THE CUSTOMER?
The customer is anyone that consumes or desires the output of a process. This may either
be an internal customer that requires the output from a process, which they then adds
further value to. It may also be an external customer who purchases the output of the
organisation’s process and desires to reap a value therefrom. A customer’s need or
requirement is termed as the voice of the customer.
Further, the external customer could also be a direct or indirect customer. A direct
customer is one who receives output from the selling organisation’s process, and generally,
these are the route to the company’s revenue as they are paid for supplying the goods and
services. An indirect customer may be one who does not receive or benefit from the
organisation’s services, but has a vested interest in what is being done (for example,
regulatory bodies or government agencies).
Customers are further referred to as cash-customers (those who pay for services and may
have a contract in place) or commissioning-customers (who determine what is required
of the process, but do not necessarily pay for it). The needs of the cash-customer are the
foremost as they make the business survive.
There is also the part in which terms of the process is determined by what the aims,
objectives and strategy the business is trying to attain. This pursuit can be termed as the
voice of the business (VoB). So, the operational process needs to be aligned to the VoB.
A customer takes an output from a process. This can be ‘true’ (end user) customers,
downstream colleagues, senior managers needing to make decisions on business
intelligence or regulatory compliance etc. Both the VoC and VoB consume output from a
process. The output(s) from a process is referred to as the voice of a process (VoP).
There is always the tension between the VoB and the VoC – customers want top quality for
very little prices and promptly, whilst the business desires to charge as much as the market
can pay within a competitive environment.
VoC
Internal Customer
External Customer
- True/End Customer
VoB
Analytics
Compliance/Audit Profit!
WASTE!
Pro
ce
ss
Ou
tpu
ts
(Vo
ice o
f P
roce
ss –
Vo
P)
- 12 -
www.makewayglobal.com © MakeWay 2019 [v4.1]
4.0 VALUE – WHAT DO WE MEAN?
Value only becomes relevant at a specific price and point in time based on the customer’s
perspective. Value represents the customer requirements, which is also referred to as the
voice of the customer, basically, what they are willing to pay for. In addition, they need to be
able to afford it.
Value can be categorised as follows.
Value term What it means
Value Add
(VA)
This feature, task, process step or output is worthwhile in the view of
the customer and they would be willing to pay for it
Business
Non-Value
Add
(BNVA)
This feature, task, process step or output is worthwhile in the view of
the business (it is necessary in some way to run efficiently or legally
etc), but it does not directly add value in the eyes of the customer
Non-Value
Add (NVA)
Waste
Neither business or customer judges this feature or task or output as
worthwhile