I’m sure many readers are trying to figure out how we came up with the “top 10” process mapping tools. How can we make such claims? And how can anyone say which process mapping tools are best? We can’t. The title does indicate “Six Sigma Process Mapping Tools”. I want to drive the message home that all the process mapping tools we’ve listed here are part of most if not all DMAIC or DFSS (DMADV for the purists) Black Belt training. Most are even covered in Green Belt training.
Before we get into the top process mapping tools we’ll begin with some key questions that help determine which is the best tool for your specific need.
- Who are the team members or stakeholders? Who has a voice and can provide input?
- What does the team consider the most important
- Uncontrolled Input Variables in the process?
- How were the Customer Requirements decided?
- Does this map reflect the current process or the one we want to create?
- Where are the measurement points in the process?
- What does your Control Plan include at this time?
- Where are the areas to be reworked identified?
- What are the non-value added processes?
- How many Input Variables did you identify (on average) per step ?
- What is the next step for the team?
One of the items I highlight when mapping a process is to find the CTSs (Critical to Satisfactions) which will drive the CTQs (Critical to Quality), which finally, will drive the CTDs (Critical to Delivery)
Takeaways from process mapping: No matter which process map best suits your needs, shouldn’t they all be visual, graphical, and practical? Easy to read for everyone from “big animal pictures” for executives to complex inter-relational diagrams (yes Venns are OK sometimes) for rocket engineers.
What is the tool?
- Graphical illustration of the process to produce the product
When do you apply process mapping?
- Starting in the “Design” phase and updating throughout
What will the tool identify?
- All value-added and non-value-added process steps
- Input Variables (X’s)
- Output Variables (Y’s)
- Data Collection Points
What comes out of the Process Map?
- Output Variables to track
- Input Variables to put into the C&E Matrix and FMEA
- Input Variables that will need to be controlled
- Possible non-value-added process steps
- Systems needing measurement studies
Here are the Top 10 Six Sigma Process Mapping Tools
1. Block Diagrams
2. Conventional Flowchart
3. Affinity Diagrams
4. Swimming Lanes
5. SIPOC – Supplier, Input, Process, Output, Customer
6. Value Stream Mapping
7. Control Plan or Preventive Maintenance Plan
8. Fishbone – Ishikawa diagram
9. C&E Matrix
10. FMEA
1. Block Diagrams
The most simplified form of process mapping, and often the first breaks down the process into boxes and simply show what goes in and what comes out, also driving the next box. Block diagrams are often used in IPO (simplified SIPOCs that prepare the process for the C&E matrix).
Process Block Diagram
2. Conventional Flowchart
Didn’t we all learn this in our first computer classes in high-school? While we think these are best for describing software algorithms, they are still commonly used to map processes.
Flowcharts are specifically decision-making tools.
Conventional Flowchart
A typical flowchart from older Computer Science textbooks may have the following kinds of symbols:
Start and end symbols
Represented as circles, ovals or rounded rectangles, usually containing the word “Start” or “End”, or another phrase signaling the start or end of a process, such as “submit enquiry” or “receive product”.
Arrows
Show the flow or direction of the algorithm or process. An arrow coming from one symbol and ending at another symbol represents that control passes to the symbol the arrow points to.
Processing steps
Represented as rectangles. Examples: “Add 1 to X”; “replace identified part”; “save changes” or similar.
Input/Output
Represented as a parallelogram. Examples: Get X from the user; display X.
Conditional or decision
Represented as a diamond. These typically contain a Yes/No question or True/False test. This symbol is unique in that it has two arrows coming out of it, usually from the bottom point and right point, one corresponding to Yes or True, and one corresponding to No or False. The arrows should always be labeled. More than two arrows can be used, but this is normally a clear indicator that a complex decision is being taken, in which case it may need to be broken-down further, or replaced with the “pre-defined process” symbol.
3. Affinity Diagram
An affinity diagram is a fun team process mapping tool where you use different color “post-it” notes and simply paste them on a wall or board. Post-it notes are great as they don’t adhere permanently, allowing the facilitator to move them around, add some, remove some, in order to see “what if” scenarios and basically keep everyone on the cross-functional team happy.
Affinity Diagram
Affinity diagrams provide a visual grouping of Client/Customer needs and help categorizes customer needs into abstract needs at highest operational levels while the lower levels contain more detailed, operational statements.
Affinity diagram exercises are team activities. Don’t forget to use different colors to represent different roles, gates, bottlenecks, etc.
How to Prepare and Affinity Diagram With Your Team:
1. Start with large list of Client/Customer needs
Have each need posted on an adhesive note on a large surface
2. Working silently and simultaneously, have each team member move needs into logical groupings
3. After notes are grouped, discuss groups and assign headings
4. Team may need to take general needs and split it into two or more specific needs
5. Take less important needs and group those that belong together meaningfully
4. Swimming Lanes
This is a great serial mapping process where the map is outlined horizontally and different teams or departments lie parallel and represent different swimmers (picture an Olympic swimming competition) of the process. As soon as the process flow-down goes into another department, then the process changes lanes.
Swimming Lanes
This is a simple process-mapping tool that identifies clear-boundaries with who does what and shows clear hand-off process points to another team or stakeholder.
5. SIPOC
The SIPOC Identifies
- Major tasks and activities
- The boundaries of the process
- The process outputs
- Who receives the outputs (the customers)
- What the customer requires of the outputs
- The process inputs
- Who supplies the inputs (suppliers)
- What the process requires of the inputs
- The best metrics to measure
Supplier – Know and work with your supplier. Help your supplier improve.
Input – Strive to continually improve the inputs. Make it easier to get it right the first time.
Process – Describe the process at a high level, but detailed enough so that an executive or a lay person would understand. Mistake-proof the process. Know it inside out. Know what works. Eliminate what doesn’t
Output – Strive to continually improve the outputs. Be the best with metrics!
Customer – Keep the customer’s requirements in sight. Stay on target. Remember the Critical to Satisfactions (CTS’).
The great thing about the SIPOC is that it’s an excellent team building tool and I put emphasis on inter-departmental cooperation here. Mapping processes at a high level is more than just writing ISO instructions or making flashy “Visios”. I love the sound of crickets in front of eight noisy people in a closed room brought on by their awestrickeness when they see how long it takes to map a SIPOC – and that’s me doing it for them on the white board not really understanding in great detail what their individual tasks are.
SIPOC Steps
- We need to get a 50,000 ft. view of the process first
- Identify the process in simple terms
- Identify External Inputs (raw materials, employees, etc.)
- Identify the Customer Requirements (Outputs) (required temperatures, lot numbers, etc.)
- Make sure to include all value-added and non value-added steps
- Include both process and product output variables
SIPOC Airline Example
Once you have an agreed upon and more importantly, understood, SIPOC – understanding the SIPOC implies that you can easily identify opportunities for improvement – you can proceed to the next step in process mapping.
6. Value Stream Mapping
A Value Stream Map is a visual tool used to document the flow of products or services through a system. A value stream is all of the actions required to change raw materials into a product delivered to the customer. The VSM differentiates the value-adding activities of a system from the non-value-adding ones. Recording the time taken for each activity shows what percentage of valuable time an object or person spends in a system. Any non-value-adding time indicates an opportunity for possible improvement within the system. The VSM shows the process flow from order to delivery and includes – a) information & material flow, b) product throughput & cycle times, c) resources utilized, d) value added times and e) location of significant waste
How To Value Stream Map
- Identify the target product, product family, or service.
- Draw a current state value stream map, which shows the current steps, delays, and information flows required to deliver the target product or service. This may be a production flow (raw materials to consumer) or a design flow (concept to launch). There are ’standard’ symbols for representing supply chain entities.
- Assess the current state value stream map in terms of creating flow by eliminating waste
- Draw a future state value stream map.
- Implement the future.
Value Stream Map
Where is it used?
Value stream mapping is a helpful method that can be used in Lean environments to identify opportunities for improvement in lead time.
Although value stream mapping is often associated with manufacturing, it is also used in logistics, supply chain, service related industries, healthcare, software development and product development.
In a build to the standard form Shigeo Shingo suggests that the value-adding steps be drawn across the centre of the map and the non-value-adding steps be represented in vertical lines at right angles to the value stream. Thus the activities become easily separated into the value stream which is the focus of one type of attention and the ‘waste’ steps another type. He calls the value stream the process and the non-value streams the operations. The thinking here is that the non-value-adding steps are often preparatory or tidying up to the value-adding step and are closely associated with the person or machine/workstation that executes that value-adding step. Therefore each vertical line is the ’story’ of a person or workstation whilst the horizontal line represents the ’story’ of the product being created.
Hand drawn versus tools
The goal is to create a map, with minimum delay, while observing the target process in situation. Thus, value stream maps are usually drawn by hand in pencil to keep the mapping process simple and allow for simple correction.
7. Control Plan or Preventive Maintenance Plan
Usually begun after the value stream map or other high-level map has been completed (SIPOC) and items such as measurement techniques or operating specifications (min/max, TAKT times, etc.)
Control Plan
8. Fishbone – Ishikawa
Is a fishbone a process mapping tool? Sure it is. Though most people think of the fishbone or Ishikawa diagram like a root cause analysis tool or way of finding out what went wrong when and where, it does get a team consensus as to what went wrong and helps highlight “wrong” ways of doing things that result in defects.
Ishikawa or Fishbone Diagram
People: Anyone involved with the process
Methods: How the process is performed and the specific requirements for doing it, such as policies, procedures, rules, regulations and laws
Machines: Any equipment, computers, tools etc. required to accomplish the job
Materials: Raw materials, parts, pens, paper, etc. used to produce the final product
Measurements: Data generated from the process that are used to evaluate its quality
Environment: The conditions, such as location, time, temperature, and culture in which the process operates
9. Cause & Effect Matrix (C&E)
The C&E matrix can use the SIPOC or IPO to drive the matrix. All C&E matrices must link to an existing process. Why create a Cause & Effect matrix for no existing process? It’s very important to capture the “as is” picture of things in order to see the “would be” or “should be”.
Cause & Effect Matrix
Having a C&E matrix that doesn’t link to a process simply indicates it was completed by an individual, not a cross-functional team. For those who feel that team process mapping efforts are a waste of time, ask yourself if you really think you know everything that’s going on in other departments or that you have mastery of every process. Bringing other stakeholders will ensure that every point of view is considered.
The C&E matrix is actually a simplified Quality Function (QFD) tool used in Design for Six Sigma (again DMADV for the purists out there) that:
- Relates the Key Inputs to the Key Outputs (Customer Requirements) using the process map as the primary information source
- Key Outputs are scored as to importance to the customer
- Key Inputs are scored as to relationship to key outputs
Some common C&E matrix outputs:
- Pareto of Key Inputs to investigate using Designed Experiments
- Pareto of Key Inputs to evaluate in the FMEA
- Input into potential sources of variation for Robust Design
- Input for developing the Process Control Plan
Team steps to completing the Cause & Effect Matrix
- Identify key customer requirements (Outputs) from SIPOC or Value Stream Map
- Rank order and assign priority factor to each Output (usually on a 1 to 10 scale)
- Identify all process steps and materials (Inputs) from the Process Map
- Evaluate correlation of each input to each output
Low score: changes in the input variable (amount, quality, etc.) have small effect on output variable
High score: changes in the input variable can greatly affect the output variable
- Cross multiply correlation values with priority factors and sum for each Input
First Pass
- Place the Outputs across the top of the matrix and rank
- Place the process steps down the side of the matrix
- Correlate process step to Outputs
- Pareto the process steps
Second Pass
- Start a new C&E Matrix with the Inputs from the top three or four process steps
- Recommended when first starting a project
-Focuses the efforts and gives the team a feeling that they’re working on the important process steps first
-Gives you a running start at the FMEA and area to focus for Robust Design
10. Failure Mode Effects Analysis (FMEA)
The FMEA identifies ways that a product or process can fail and helps mitigate actions to remove inherent failure modes before they ever occur. The FMEA assumes that the process is in control and capable of meeting the process spreads used in the design.
- It also assumes that material, and components are performing as specified in the design documentation.
- Failures can be caused by:
Unclear specifications
Inadequate knowledge of environmental conditions
Insufficient Analysis, Modeling and Simulation
Poor Design
Insufficient Testing
Not designing for process requirements
- Controls are related to the design process:
Prevention – Analysis, Simulation and Modeling
Detection – Prototype Testing, Design Verification Testing, Reliability Testing
Failure Mode Effects Analysis (FMEA)
The FMEA approach:
- Identifies the ways in which a product can fail
- Estimates the risk associated with each failure mode
- Rank orders the failure modes to prioritize the design teams efforts
- Tracks corrective actions and provides a permanent record for subsequent design and process FMEAs
How to Complete an FMEA
- Develop a block diagram of the Design Item / Function being analyzed. This can be a product, system, sub-system, and or component
- For each Design Item / Function, determine the ways in which it can fail (Failure Modes)
- For each Failure Mode associated with the item, determine Effects of the failure on the customer
- Remember the internal customers!
- Identify potential Causes of each Failure Mode
- List the Current Design Controls for each Cause or Failure Mode
- Create Severity, Occurrence, and Detection rating scales
- Assign Severity, Occurrence and Detection ratings to each Cause
- Calculate the RPN for each Cause
- Determine Recommended Actions to reduce high RPNs
- Take appropriate actions and recalculate RPNs
FMEA Output – The Risk Priority Number (RPN)
The output of an FMEA is the Risk Priority Number
The RPN is a calculated number based on information you provide regarding
- the potential failure modes,
- the effects, and
- the current ability of the design process to detect the design failures before reaching the customer
It is calculated as the product of three quantitative ratings, each one related to the effects, causes, and controls:
RPN = Severity X Occurrence X Detection
Process Mapping Summary
I want to conclude by suggesting that all processes you map, should be able to indicate which key metrics to measure and report. Here are some pointers for the not so obvious.
- Measure things that matter – to our customer (Critical to Satisfaction)
- Measure consistency reduce and understand variation (Critical to Quality)
- Monitor and evaluate performance (Critical to Delivery)
- Measure conformance to the process
- Identify improvement opportunities
- Make your metrics practical and graphical
- The right metrics drive the right behaviors
