Some Lean Six Sigma tools: define and measure

Lean Six Sigma cost, speed and quality jumps are obtained

by applying the right tools. Following the DMAIC

Lean Six Sigma improvement model, we will analyze a series of

tools of each phase.

The definition phase

Purpose of defining:

This phase of Lean Six Sigma implementation identifies the

improvement opportunities and customer deliverables and defines a

scope. At the end of the definition phase, we should have a project

statute, clearly identified stakeholders, a project team,

estimation of business implications, a customer assessment

requirements, a high-level process map and project management and

communication plans.

Tools to define:

Stakeholder analysis:

The different stakeholders (customers, shareholders, employees) are

listed and the potential impact of the improvement project on each of them evaluated as substantial, average, low or null.

SIPOC diagram:

Of the tools applied in this stage of the improvement project,

perhaps the most widely used is the SIPOC diagram. SIPOC supports

for Suppliers, Supplies, Processes, Outputs and Clients. The diagram

provides a visual answer to the questions needed to understand

the process: who are the main stakeholders in this process? That

value that creates? Who is the owner of the process? Which are the

inputs and who provides them? What resources does the

process? What steps in the process create the value?

The steps involved in creating the SIPOC diagram and the

participation of team members in brainstorming and generating ideas

The sessions are as important as the resulting diagram.

VOC – Voice of the Customer:

Critical for a proper definition of the improvement project is the

availability of data representing customer views and

requirements. These are collected using VOC tools such as interviews,

surveys, focus groups, comment cards, suggestion / complaint boxes

etc. The definition of customer here includes internal and external


Using Kano analysis hides raw quantitative and qualitative data

obtained from the above in clearer expressions of the value

Customers place on various features of products and services that you offer.

Developing Critical Quality Requirements Converts the Customer

statements, which may be imprecise, to precise requirements (valued

from the customer’s perspective) for your product or service.

The measurement phase

Purpose of the measure:

This phase quantifies the current state of the process with respect to

cost, speed and quality and provides insight into the gaps that are due

full. At the end of this phase, we have a detailed map of the

process, data on key input and output variables, an analysis of the

process capability, bylaws and refined project plans where

justified by new information and recommended actions to choose under

hanging fruit.

Tools to measure:

Operational definition: several measures are defined so that all

Team members apply the same definitions when collecting data for the

improvement project.

Process map, value stream map, complexity value stream map:

This produces a more detailed representation of the process than

the SIPOC diagram and includes information such as wait times,

processing times, resource

consumptions, process operator, etc.

Cause effect matrix:

This tabulates causes versus effects and calculates the scores that

they are used to classify causes. As a measure

tool, this matrix is ​​used to select which inputs to focus on

due to its significant impact on the results of the process.

Preliminary FMEA (Failure Modes and Effects Analysis):

This tool has a similar function to the cause and effect matrix.

All possible input failures are considered, and then

weighted according to

to the probability of occurrence, severity of the impact on the products and

difficulty of detection. This evaluation also helps determine

what inputs the project team should focus on.

Data collection plan:

This includes decisions about what data (balanced between input and

output) to collect, identification of

stratification factors (these help determine patterns in the data),

determination of sample size, identification of data sources,

preparation of data collection and data allocation sheets

collection duties among team members.

Pareto charts:

This is one more tool to focus the team’s efforts on the most

major problems. A Pareto chart is a bar

graph where the horizontal axis represents categories. That

vertical axis we can plot in descending order, the frequency of

occurrence, or cost, speed or impact on the quality of each category.

Where there is a clear Pareto effect, only some of the categories

(typically 20% or less) are responsible for most of the effects

(80% or more).

Measurement systems analysis:

The measurement process undergoes standard analysis to ensure reliability, repeatability, and reproducibility. Other attributes of

the measurement system are stability, bias and discrimination.

Control charts:

A control chart is a sequence of quantitative data run charts with

three horizontal lines showing a middle centered and top and bottom

control limits. Control charts help to assess the nature of

process variation. Processes under control are expected

produce data points randomly distributed around the mean but within

calculated control limits.

Process capacity assessment:

This tool measures the capacity of the process and assesses the capacity of a

process to meet functional requirements.

There are several measures of capacity. They all compare

Process the standard deviation to the allowable range of variation as

specified by the customer.

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