Tips, tricks and ideas for analysing

real-life data sets in Minitab

Quentin Brook

Minitab Insights, Philadelphia 2016

Process improvement

consultant and author.

Live in Winchester, UK.

Married, father of two.

Fishing, running and pubs.

linkedin.com/in/quentinbrook

Quentin Brook

Checking and preparing data

Understand where it came from.

Check it represents what you think it does.

Get a feel for its quality.

Prepare it for further analysis.

Checking and preparing data

Let’s take a look at some real data…

Take your time – it’s an investment.

Don’t assume anything!

Checking and preparing data

First Pass Analysis

To gain a rapid, high level understanding of

historical process performance.

To get to know the data and look for clues

for further analysis.

First Pass Analysis

Let’s take a look at our real data…

Sample ‘window’

Time

Collection ‘moment’

Lead time data collection issues

1404124810929367806244683121561

200

150

100

50

0

Index

Tim

e t

o r

eso

lve

Time Series Plot of Time to resolve

Lead time data collection issues

Lead time data collection issues

15101359120810579067556044533021511

200

150

100

50

0

Index

Tim

e t

o r

eso

lve

of Time to Resolve ordered by Open Date but with data cut off at end of sample peri

Lead time data collection issues

1404124810929367806244683121561

200

150

100

50

0

Index

Tim

e t

o r

eso

lve

Time Series Plot of Time to resolve ordered by Resolve date

Be inquisitive – look for strange things, but

don’t read too much into the minutiae.

Have a play with the data – there are no

rights or wrongs.

First Pass Analysis

What to do with too much data.

What to do with too much data.

XBar-R Charts

Sampling

Let’s take a look at our real data…

What about Normality?

What about Normality?

Non-Normal data ≠ bad data!

Investigative analysis

Investigative analysis

Don’t just jump right in!

What’s your theory > What graph is right for the job?

It’s at this point that there’s a gulf between basic

spreadsheet software (e.g Excel) and specialist

software (e.g Minitab).

Some analysis examples from our real data…

Keeping track of your analysis.

‘Storyboarding’ is the key!

Be diligent – summarise as you go in the ReportPad.

Keeping track of your analysis

Using ReportPad with our data…

In summary

Take the time to get to know your data.

Be inquisitive and ‘listen to your data’.

Don’t worry too much about Normality.

Let your theories and ideas drive your analysis,

then choose the right graph.

Storyboard as you go, or regret it later!

Thank you.