2. Introduction to Pareto diagram
Pareto diagram( Pareto analysis) is among seven
quality control tools
It is a bar graph. The lengths of the bars represent
frequency or cost. It visually depicts situations
which are more significant.
It is used while analyzing frequency of problems or
causes in a process and it helps us to find the
cause which generally responsible for occurrence
of problem
According to Pareto diagram in almost every
case,80% of the total problems incurred are
caused by 20% of the problem cause type,
therefore by concentrating on the major problems
5. Major Causes of potholes
Water is the major cause of potholes
Falling rocks in cuttings
Poor road design over certain sub grades
(expansive, collapsible, dispersive)
Diesel (or other chemical) spillage
Animal hooves in hot weather
Excessive soluble salts
Mole rats tunneling under the road
Mechanical damage
Water erosion along unsealed joins
Ravelling under traffic
6. Temporary wet conditions (eg, seepage,
localised irrigation, etc)
Especially overloaded trucks
Heavy vehicles cause road to deflect
Repetition causes cracking and fatigue
Allows entry of water which is pumped under
pressure together with loosened fines
Deeper seated problems
When accompanied by severe cracking and
deformation or distortion of the surfacing
Differ from those areas with no cracking, which
originate from water penetration at the surface
7. Identification of symptoms that account
for 80% frequency
Below are points accounts for cause which is causing
problems most of the time
Water is the major cause of potholes
Water makes road soft and thus mechanical damage
occurs
Water erosion along unsealed joins is also a cause which
comes under water
Temporary wet conditions (eg, seepage, localized
irrigation, etc) deteriorate road conditions and it comes
under water category.
Entry of water under pressure together with loosened
fines
Water penetration at the surface of road
8. Problem definitions
As we can read that there are many causes which
appear synonyms as they are sub category of one
cause. Thus, after analyzing all causes we get a a set
of significant causes. They are-
Water Problem
Falling rocks in cuttings
Poor road design
Diesel (chemical) spillage
Animal hooves in hot weather
Traffic
Overloaded trucks/Heavy Vehicles
9. Percentage contribution of all causes to
potholes
S.No Cause Percentage contribution
in potholes
1 Water Problem 75
2 Falling rocks 10
3 Poor road design 45
4 Diesel spillage 28
5 Animal hooves 12
6 Traffic 28
7 Heavy Vehicles 30
11. Lessons learned by team
About Pareto diagram. What it is all about and
what it shows.
How to decide which causes are responsible for
majority of problems
How to make pareto diagram