process mapping workbook - issp |...
Post on 21-Mar-2018
241 Views
Preview:
TRANSCRIPT
Copyright ISSP 2011 1
Institute of Six Sigma Professionals
Process Mapping Workbook
Developed by Gillian Clark
Copyright ISSP 2011 2
Table of Contents
Introduction .............................................................................................................. 3
PART 1 ..................................................................................................................... 4
Processes and Systems .............................................................................................. 4
Processes .............................................................................................................. 4
Systems ................................................................................................................ 5
Business Processes ................................................................................................. 5
Why use Process Mapping? ......................................................................................... 7
Purpose for Mapping a Particular Process ...................................................................... 8
Process mapping tips ............................................................................................... 10
Methods of Process Mapping ..................................................................................... 12
Supplier-Input-Process-Output-Customer (SIPOC) .................................................... 12
Flowchart ............................................................................................................ 15
Swimlanes ........................................................................................................... 16
Multi-Level Flowcharts .......................................................................................... 17
Flowchart Symbols ............................................................................................... 18
ASME symbols .................................................................................................. 19
The process of process mapping ................................................................................ 21
PART 2 ................................................................................................................... 23
Xs and Ys ............................................................................................................... 24
Worked Example – Xs and Ys................................................................................. 24
CNX ....................................................................................................................... 25
Worked Example - CNX ......................................................................................... 25
Specifications .......................................................................................................... 26
Worked Example - Specifications ............................................................................ 26
Value Adding .......................................................................................................... 26
Worked Example – Value Adding ............................................................................ 27
Copyright ISSP 2011 3
Introduction Process Mapping is a widely used tool in many, if not all, business improvement toolkits.
Six Sigma adds extra levels of detail, in very specific ways, in order to assist with Defining
and then Measuring problems.
Part 1 of this workbook describes Process Mapping in general, giving information on
different methods that can be used, as well as tips and techniques that may be helpful.
Part 2 describes the additional levels of detail required in a Six Sigma project. If you are
experienced in Process Mapping and confident that you can develop an accurate visual
representation of a process, including all feedback loops, then you may want to skip
straight to Part 2.
Copyright ISSP 2011 4
PART 1
Processes and Systems
A key objective in many Six Sigma projects is to greatly improve the efficiency of a system,
the performance of a process, or even the output of a machine. This, therefore, requires
an in depth understanding of the processes involved, the critical process variables and how
the processes are interlinked in systems.
Processes Simply put, a process is a series of actions, changes or functions that transform inputs into
outputs – hopefully the desired result, but potentially including unwanted outputs that Six
Sigma projects may be used to resolve.
We put something in, alter or affect it and receive something different out the other side.
The inputs to a process are generally outputs of other processes; and the process itself
usually involves people, equipment and materials – both tangible, such as steel, and
intangible such as incoming data. The key point to remember is that a process always
changes the input – otherwise it is not a process.
Hardware (e.g.
mechanical
parts)
Data/Info. (e.g.
financial
figures)
Services (e.g.
transport)
Software (e.g.
computer
programme)
Polic ies
Mater ials
Procedures
Methods
Information
People
Skills
Knowledge
Training
Plant/Equipment
Environment
INPUTS OUTPUTS
Transformation of
inputs
Results
(Per formance
Indicators)
G660
Copyright ISSP 2011 5
Systems
A system is simply a group of interacting, interrelated or interdependent processes that
combine to perform a more complex outcome.
Business Processes
The traditional view of corporate hierarchy, with ‘heads of’ in each department, can lead to
various empires of departmental silos. There are probably good streams of communication
and cooperation within the ‘silo’ but less cooperation and communication from other ‘silos’.
Each silo functions independently, creating less flexibility in the overall system.
Copyright ISSP 2011 6
The business processes, or drivers, often cross departmental boundaries. These affect all
parts of the business, so we can see the importance of having good communication
between ‘silos’. Taking a unilateral decision in one silo may well have adverse affects in
other areas.
Some further examples of business processes are:
Customer Oriented Processes Management and Support Processes
Winning business Business Planning
Fulfilling a customer’s order Recruitment
Design and development Maintenance of fixed assets
Chrome plating a product Producing financial accounts
Assembling a product Performance measurement and management
Packing and Delivery
Raising the invoice
Note how some of the processes listed above could be included under others, for example
‘packing and delivery’ could be included under ‘fulfilling a customer’s order.’ In addition,
‘winning business’ may provide information into ‘performance measurement.’ This
emphasises how the processes are all interlined into systems and also highlights how
important it is to define the boundaries of a process or project before beginning work.
Copyright ISSP 2011 7
Why use Process Mapping?
Even when a process is simple, and potentially easy to understand, it is important to
produce a process map. This can include input variables, measurement points, tasks, and
output variables at each process step; and when done correctly can highlight many issues
that were otherwise not apparent. In addition, a Six Sigma project requires more, and
often different, details to other Business Improvement projects, and plotting this data
visually can help with more detailed understanding of the process, alongside the Analysis
phase of the DMAIC cycle.
Other benefits include:
• Process Mapping provides an overview of a process – showing how inputs, outputs
and tasks are linked
• The map provides all team members with a common understanding of the
complexity of the process, including potential sources of variation and defects.
• Process Mapping helps to visualise the linkages between information and physical
flows
• Process maps give a clearer explanation of a process than words ('a picture paints a
thousand words.')
• There is a better understanding of the process by the mere fact of mapping it, even
without further work.
• It is also the first step of good business process re-engineering.
• Process Mapping can allow teams to dig deeper into each department, creating sub
maps
• Process Mapping can provide the base information to highlight areas where further
improvement projects can assist.
Copyright ISSP 2011 8
Purpose for Mapping a Particular Process
There are many different ways to visually represent a process, and thinking about the
purpose behind looking at a specific process can help with the decision of which process
mapping method to choose. For example, the reason for looking at a particular process
may be:
• To reduce cost
• To reduce space
• To reduce leadtime
• To improve customer service, or
• To move towards automation
Thinking about the purpose for mapping also helps you identify where to go into more
detail. The mapping would be done at different “flight levels” for different reasons:
• Enterprise Understanding - High Level
• Macro Planning - Mid Level
• Lean Events/Kaizens – Very Detailed
In the same way that a Six Sigma project as a whole follows the DMAIC cycle, and Defines
a problem before Measuring data, defining the purpose of process mapping also helps
determine what information to collect and which process mapping technique might be most
suitable.
Potential data that can be incorporated into a process map
Tasks and activities Cycle Times
Data points Work in Progress
Flow time Sequence
Loops Travel / Distance
Quality and defect rate Process specifications
Number of people involved Information required
Departments involved Etc.
Copyright ISSP 2011 10
Process mapping tips Regardless of the method chosen to map a process, there are a number of steps needed in
order to ensure an accurate representation:
• Record all activities as they are actually done, not as they should be done, as the
book says they’re done, or as they used to be done!
• Visit the process, observe carefully and ask questions
• Be aware of statements like, “We usually do it this way.” – Identify the exceptions
and rework loops as well.
• Start each activity box with a verb to describe what is happening
– E.g. ‘print’, ‘collate’, ‘decide’, ‘calculate’, ‘design’, ‘weld’
• Get the right balance between brevity and detail – a decent representation of a
process has probably no more than 20 activity boxes.
– Remember that a process step can always be expanded into more detail
later, if required
• Walk the process downstream to understand what happens and then back upstream
asking ‘Why do things that way’?
• Always date maps, agree version control and person responsible for changes
• Do not discard any issues identified, improvement ideas, questions, observations
and out of scope comments - record on different coloured ‘post-it’ and set aside.
• Also consider if the step adds value, from the customer’s perspective.
• Are there any self-imposed constraints on the process?
Copyright ISSP 2011 11
The project team have primary responsibility for creating the process map. It is important
to acquire the process map within reasonable time scales, otherwise the organisation may
lose interest in the project if the map takes months to produce! To facilitate rapid mapping,
the team should be cross-functional, with team members from each department that the
process touches – and ideally with the process customer as well. Note that the process
map should be as simple as possible, whilst showing the necessary information; if it looks
like a map of the London Underground, probably there is too much detail!
Copyright ISSP 2011 12
Methods of Process Mapping
Supplier-Input-Process-Output-Customer (SIPOC)
A SIPOC is a high-level process map that is typically used during the Define phase of a Six
Sigma project. It is used to clearly define the purpose and scope of a project, as well as
identifying relevant customers and stakeholders who may need to be consulted.
It is a starting point in identifying the voice of the customer (VOC) and provides an
overview of the key inputs (or X variables) of a process [Y=f(X)] that may have significant
impact on the critical outputs (or Y variables.)
It is also very helpful when producing a more detailed process map. Once all the suppliers
and customers, inputs and outputs have been noted on a SIPOC, it can be used as a
checklist to ensure the detailed process map has covered all aspects required.
Typically a SIPOC is constructed as a simple 5 column table, with simple brainstorming
from a cross-functional project team.
1 Product delivery date Invoice 1 Client
2 2
3 Due date 1 Accounts receivable
1 Client data 2
2 1 Check client terms Sales data 1 Sales
3 2 Write invoice 2
1 Payment terms 3 Print invoice VAT data 1 Accounting
2 4 Address and send invoice 2
3 5 Record data with sales 1
1 VAT rules 6 2
2 7 1
3 2
6
OUTPUT CUSTOMERS1
2
3
4
5
SUPPLIERS INPUT PROCESS (High Level)Process Name: Issue Invoice
4 Legal
Operation or Activity
End Point - Sales receive data
1
2
3
Operations
Sales
Accounts
Start Point - receipt of delivery note
Although it is possible to work through the table from left to right, it is often easier to
produce in the following order, with iterative loops as the team develops the SIPOC:
1) Agree and name the process under consideration
2) Define the exact start and end points of the process under consideration
a. What event triggers the process and what event marks the end of the
process – establish clear boundaries to prevent project scope creep
3) List the 5 or 6 main steps in the process
Copyright ISSP 2011 13
a. This is optional, as it is generally only used as a memory jogger for the rest
of the SIPOC, especially as it will usually be superseded by a more detailed
process map later in the project
4) Identify all the customers, internal and external, who receive something from the
process
a. This will include the next step in a business process, but will also include
other internal departments e.g. for management performance information
b. This includes customers of each of the sub-steps within the overall process,
as well as the final customer. For example, one sub-step may pass a
document onto a different department, and the product on to the next sub
step – in this case, the other department would be noted.
5) Identify all the outputs of the process – anything that is produced by the process as
a whole
a. This includes the product, information, service, and/or decisions that are
produced
b. This might be customer facing, internal information, value adding or non-
value adding etc
c. It is not important to align the outputs (at this stage) with the exact process
step. It is important merely to capture them all
6) Identify all the inputs to the process
a. Inputs are material, information, and/or services that are required by the
process to produce the outputs.
b. It can even include factors that influence the process. For example, in a
bakery, environmental factors such as outside temperature can impact the
process.
7) Identify all the suppliers to the process – all individuals, departments or
organisations that provide anything to any part of the process
Copyright ISSP 2011 14
a. These can be internal (e.g. department, division, or individuals) or external
(e.g. vendors, government, or individuals).
b. It is also possible that a supplier is also a customer.
8) Review all the stages and ensure that all the Inputs have their Suppliers listed, and
all Suppliers have all their inputs recorded. Ensure all Outputs have a Customer,
and vice versa.
9) If required, additional performance information can be added
a. Customer specifications for the process performance
b. Process limits
c. Supplier performance – how capable are they at meeting the process, or
customer, requirements?
Copyright ISSP 2011 15
Flowchart
Detailed process mapping will be required as the project progress from DEFINE into the
MEASURE and ANALYSE stages. There are a number of different formats that can be used,
depending on the type and level of information required. This is why it is important to
Define the purpose of mapping the process before choosing the method, and starting to
map.
A process map can be a simple flowchart that depicts a sequence of activities/tasks with
little or no additional information:
Alarm goes
off
Turn off
alarm
Groan
Shake
spouse
Crawl out
Bath
chores
Breakfast
Grumble
Set alarm
Dark?Turn on
light
Spouse need
money?
Below 60°?Back to
bed
Turn on
heat
Give £50
Below 70°?
Kiss
spouse
Kiss
spouse
Resolve to
set alarm
earlier
Walk to
car
Drive to
work
Married
> 5 years?
Marrried
>1 year?
Yes
No
Yes
No
Yes
No
Yes No
No
Yes
No
Yes
Process of getting
to work!
Copyright ISSP 2011 16
Swimlanes A Cross-functional flowchart, or swimlane process map, describes the process in terms of
the function (or personnel) responsible for each activity/task. Other variations are a
vertical, rather than a horizontal orientation. Information regarding the duration of the
tasks, costs, etc. may also be included.
Copyright ISSP 2011 17
Multi-Level Flowcharts Multi-Level flowcharts enable more detail to be shown. Usually, a process is first described
using a high level (macro-level) flowchart which provides a clear overview of the steps
involved. Where deemed necessary, ‘drill down’ may be carried out, i.e. a particular step
may be described in greater detail by a lower-level (micro-level) flow chart. For a complex
process, this principle may be extended to include a number of levels of flowchart. The aim
is to keep each level of flowchart separate so that the clarity of the information is ensured.
IDEF0 is a more formal system of this general method.
Process step 1 Process step 2 Process step 3 Process step 4
Sub-process
step 1
Sub-process
step 2
Sub-process
step 3
Sub-process
step 1
Sub-process
step 2
Sub-process
step 3
Level 1
Level 2
Level 3
Copyright ISSP 2011 18
Flowchart Symbols Along with the variety of flowcharts, there are many possible symbols which may be used.
Some flowcharts are produced to meet specific industry needs such as data processing and
use specialist symbols such as those described in BS 4058. However, there are some basic
flowchart symbols available which are likely to meet more general needs. Some widely
used symbols are described below:
Name Symbol Description
Terminator The start or end of a process. Each strand of a process
must have a start and an end, at some point.
Activity Process step, or activity. Often represented by a post-it
note!
Activity Used if the activity is described in greater detail by a
lower level flowchart.
Decision This represents a decision point in the process, where
two or more different process steps may occur
depending on the decision outcome. Generally, the most
common outcome, or the ‘positive’ decision, is given the
most direct route out of the decision box; i.e. if the
flowchart is mapped horizontally, the ‘yes’ route is to the
right, while the ‘no’ is to the bottom.
Multiple
documents
This represents multiple copies of a document, e.g.
copies of a test report
Connector This is used if a flowchart has to be split due to space
constraints. An identifier such as a letter of number is
included in the circle to link the two ends of the broken
flowchart.
When using post-it notes to map a process, it is often helpful to colour code them; for
example yellow = process step, orange = headings, pink = issues, green = possible
solutions. If coloured post-it notes are not available, different coloured marker pens can be
used for a similar effect.
Copyright ISSP 2011 19
ASME symbols
An alternative set of symbols, also widely used, are the set of five symbols described in BS
3138 and ASME 101. Rather than containing text or other characters, often, these symbols
are associated with external text, e.g. a listing of process operations is annotated with the
appropriate symbol. These useful symbols are shown below:
Name Symbol Description
Operation Usually describes a transformation process, e.g. a value-
adding activity which converts raw material into saleable
product.
Transport This symbol is used to show the movement within the
process of materials, equipment, people, etc.
Inspection This symbol shows an inspection/checking activity.
Storage This symbol represents controlled storage in which
material is received into a storage location or issued from
a store. It may also be applied to samples which are
retained for reference purposes.
Delay This symbol shows a delay in the sequence of events,
e.g. items queuing between operations.
Copyright ISSP 2011 20
This Work Combination Table is another way of representing a process. Each step in the
process is described, and then the ASME symbol highlights what type of activity it is.
Copyright ISSP 2011 21
The process of process mapping Regardless of the method used for detailed process mapping, it is important to follow a
systematic process, in order to capture all the information required.
1. Define and agree the purpose of the project
a. What are you trying to improve, so what do you need to Measure?
2. Define and agree the scope and boundaries of the process (the ‘start’ and ‘end’ points)
a. For example, do you start to map ‘Production’ at receipt of raw material, or
receipt of a customer order?
3. Identify the customer(s), both external and internal
a. If your project is centred around reducing costs or improving uptime, who is the
beneficiary?
4. Identify the product and the characteristics that are important to the customer (output
variables)
a. What are the key characteristics that the customer needs from the product?
i. Physical characteristics
ii. Chemical properties
iii. Performance attributes
b. If your project is focused on internal needs, what are the company goals?
i. Lower costs
ii. More equipment uptime
iii. Less scrap and off-quality
iv. Less rework.
5. List raw materials obtained from suppliers, both internal and external.
a. Note that data may be seen as a ‘raw material’ depending on the process
6. Segregate the flow into departments using ‘Swim Lanes’, if method requires this.
7. Record each step in the process in a separate activity box - using post-it notes allows
for rapid changes as the process map develops.
8. Brainstorm all activities in the process – sort, organise and combine where appropriate
9. Look to establish a clear input and output for each step
a. The output of each process step should be the input to a following one
Copyright ISSP 2011 22
b. The input to each process step should be the output of a preceding one.
10. Add rework or recycle loops as relevant
a. Indicate any points where material is removed from the process because it
needs additional work to be upgraded to first quality
b. Use lines and arrows to show where the material is reintroduced to the normal
process flow – writing these onto post-it notes keeps the process map flexible
c. Chemical recycle streams should also be noted.
11. Go and visit the work to see what the process actually is – ‘Gemba’ walks
12. Aim for an overall ‘picture’ that everyone can understand
13. Use sub-processes if needed
14. Remember to include activities that happen infrequently, such as monthly cleaning,
preventive maintenance, seasonal changes, etc.
15. Leave space at the bottom to attach documents, where appropriate.
Copyright ISSP 2011 23
PART 2
Once a process has been mapped, or often during the mapping process, additional detail
can be added to assist with the Six Sigma project. Specifically, the following information:
• Xs and Ys (Inputs and Outputs)
• Cs, Ns or Xs (Constants, Noise or Variables)
• Specifications
• Value and Non-Value Adding
The following basic process map will be used as a worked example throughout this section,
to illustrate the details required.
Copyright ISSP 2011 24
Xs and Ys When mapping a process, it is often helpful to identify the key inputs and outputs at each
stage of a process. The key inputs are often referred to as the ‘Xs’ or ‘Key Process Input
Variables’ (KPIVs), while the outputs may be known as the ‘Ys’ or Key Process Output
Variables (KPOVs).
A causal relationship exists between the Xs and Ys; in functional notation, this relationship
can be expressed as: Y = f(X1, X2, ....XN); i.e. an output variable, Y, is dependent on one or
more input variables, Xs.
The traditional approach to processing often focuses on the output; typically the Ys are
monitored for conformance to specification, and if there are problems, some action is taken
on the Ys, e.g. rework, scrap, etc. In six sigma, attention should be focussed on the Xs,
rather than the Y:
Xs Y
Process Input Process Output
Independent of Ys Dependent on Xs
Causes of problems with Ys Effect of the Xs
A symptom
Eliminated or controlled during processing Are monitored
Worked Example – Xs and Ys List the output variables (Ys) for each step, for both product and process.
Copyright ISSP 2011 25
List the input variables (Xs) for each process step.
CNX Input variables can be classified into three categories:
‘C’ – those variables that must be held ‘Constant.’ These require a standard
operating procedure (SOP) to ensure consistency.
‘N’ – those variables that are uncontrollable, or ‘Noise,’ or cannot be cheaply or
easily held constant.
‘X’ – those variables considered to be key process, or ‘eXperimental.’ These can be
tested in order to determine what effect each has on the output, and their optimal
settings to achieve desired customer output. Note, whilst controllable variables are
the obvious choice for experimentation, some noise variables can also be controlled,
if only during an experiment.
Worked Example - CNX Partition the input variables into CNX
Copyright ISSP 2011 26
Specifications If a variable is not being held constant, what are the specifications that a process has to
work with?
Specs could be given by the customer
Could use historical data
Can guess, using previous knowledge and experience
Worked Example - Specifications Add the operating specifications & process targets for the C & X variables (if available).
Value Adding Determining which process steps are value adding is a judgement as to what meets the
customer’s needs. It is similar to the ‘7 Wastes’ tool in Lean, but is not quite the same.
The purpose in doing this is so the Six Sigma project can experiment with what is important
to the customer – hence CTQ (Critical to Quality) and/or VoC (Voice of the Customer) is
important. The process steps judged as ‘value adding’ may differ, depending on the
customer’s view. Using the tea-making example, one customer may view the brand of tea
as important, while another may like the type of cup (bone china tea cup versus large
mug?) The Six Sigma project would then hold different things constant, depending on what
the customer values in the process.
Copyright ISSP 2011 27
Worked Example – Value Adding Note, in this version, the customer is not interested in the brand of tea - or perhaps the
project is to determine how to make the best cup of tea with a particular brand.
Here, the customer is interested in: a hot cup of tea, at the ‘right’ strength, with the ‘right’
amount of milk and sugar.
The step of ‘Boil Water’ is categorised as ‘Noise’ as there is fluctuating electricity from the
National Grid. This means the time taken to boil the water will vary. The final temperature
of the boiled water will also vary at different heights above sea-level. Although the step is
rated as ‘Value Adding,’ there will be no experimentation with the input variable – it is not
an ‘X.’
Conclusion Process Mapping is a vital tool for any Business Improvement project. Six Sigma projects
generally aim to reduce variability and to strive for perfection by controlling inputs. It is
therefore essential to identify all pertinent input variables before starting any
experimentation. The methods outlined in this document will help with the accurate
mapping of a process, as well as the accurate categorisation of process steps and inputs.
top related