Making Better Decisions Making Better Decisions – WHAIP Info for Action course 25 June 2012 Presenter: Mike Davidge
Making Better Decisions Why do we analyse and present data? Source: Robert Lloyd IHI 2006 To understand the variation that lives within our data To help us make good management decisions in the way we react to that variation
Making Better Decisions But often we have presented data in a different way...
Making Better Decisions The change in Merthyr is remarkable
Making Better Decisions Eco-friendly
Making Better Decisions Nomination for the Turner Prize
Making Better Decisions We have 2 quarterly data points - is this an improvement? Higher is better
Making Better Decisions Are we assuming something like this?
Making Better Decisions But it could be like this...
Making Better Decisions Or this...
Making Better Decisions Or this!
Making Better Decisions Why do our processes vary? Mrs Jones runs a B&B establishment in a seaside town. She makes breakfast every morning for her guests before going off to do a cleaning job in the local factory. Recently she has been late and her supervisor has given her a verbal warning. What can she do to avoid being late in future? Her son has been measuring her finish times as part of a GCSE maths project. Let’s look at the results
Making Better Decisions Why does her finish time vary?
Making Better Decisions Walter A. Shewhart (early 1920’s, Bell Laboratories) While every process displays variation: some processes display controlled variation (common cause) stable,consistent pattern of variation constant causes/ “chance” while others display uncontrolled variation pattern changes over time special cause variation/“assignable” cause
Making Better Decisions The variation in Mrs Smith’s process Common Cause = Consistent over time & part of the process Special Cause = Irregular in time & indicates a changed process Group the causes into common & special Are there any that cannot be grouped?
Making Better Decisions Shewhart’s purpose Data contains both signal and noise. To be able to extract information, one must separate the signal from the noise within the data. To fulfill that purpose he created the control chart
Making Better Decisions Upper process limit Mean Lower process limit A typical process control chart (SPC chart)
Making Better Decisions What constitutes a change? The MBFC Index You will need a coin And two free hands! Just how competitive can you get?
Making Better Decisions How often to measure? Barnsley stroke pathway time in hospital before getting onto stroke ward
Making Better Decisions Monthly data shows improvement
Making Better Decisions Weekly data tells a different story
Making Better Decisions Rules for special causes Rule 1 Rule 2 Rule 3 Rule 4 Any point outside one of the control limits A run of seven points all above or all below the centre line, or all increasing or all decreasing Any unusual pattern or trends within the control limits The number of points within the middle third of the region between the control limits differs markedly from two-thirds of the total number of points
Making Better Decisions X X X X X X X X X LCL UCL MEAN X X X X X X X X X X LCL UCL MEAN X Point above UCL Point below LCL SPECIAL CAUSES - RULE 1
Making Better Decisions MEAN Seven points above centre line SPECIAL CAUSES - RULE 2 LCL UCL LCL UCL X X X X X X X X X X X X X X X X X X X X X Seven points below centre line
Making Better Decisions MEAN Seven points in a downward direction SPECIAL CAUSES - RULE 2 LCL UCL LCL UCL X X X X X X X X X X X X X X X X X X X X X Seven points in an upward direction
Making Better Decisions SPECIAL CAUSES - RULE 3 X X X X X X X X X X X X X X X X X X X X Cyclic pattern X X X X X X X X X X X X X X X X X X X LCL UCL LCL UCL Trend pattern
Making Better Decisions SPECIAL CAUSES - RULE 4 Considerably less than 2/3 of all the points fall in this zone X X X X X X X X X X X X X X X X X LCL UCL X X X X X X X X X X X X X X X X X X X X X X X X X X LCL UCL Considerably more than 2/3 of all the points fall in this zone
Making Better Decisions
PROCESS 3 X X X X X XX X X X X X X X X X X X X X X PREDICTABLE? YES / NO / NOT SURE RULE
Making Better Decisions PROCESS 4
Making Better Decisions
What decision do you make? Is your information presented in a way that allows you to confidently make one of these decisions? DecisionBecause Do nothingPerformance ok Contingency plansSpecial cause variation Process redesignCommon cause variation Making Better Decisions
So why run or control charts? One picture, one message Shows change over time Allows you to see variation and differentiate between signal and noise Helps you to make the right decision Hospital X
Making Better Decisions SPC tools Baseline Winchart from Prism Europe Chartrunner from PQ Systems ARTrunner.php
Making Better Decisions Useful references Donald Wheeler. Understanding Variation. Knoxville: SPC Press Inc, 1995 Donald Wheeler. Making sense of data. SPC for the service sector. Knoxville: SPC Press Inc, 2003 WE Deming. Out of the crisis. Massachusetts: MIT 1986 American Society for Quality Donald M Berwick. Controlling variation in health care: a consultation from Walter Shewhart. Med Care 1991; 29: Walter A Shewhart. Economic control of quality of manufactured product. New York: D Van Nostrand 1931.