March 1, 2020
By Darren Dolcemascolo
In last month's article, we talked
about the first part of a problem
solving process: defining the problem.
This month, we are going to talk about
gap analysis. This is the process
by which we identify the critical causes
or root causes to a problem. A gap
analysis involves investigation.
The problem solving team must deeply
understand the process, collect relevant
data, and then analyze the data in order
to determine what are the critical
The first step in gap analysis is to
observe the process in detail.
Documenting the current state process
utilizing a process map is a good way to
get started with this process. The
team may even do this as part of the
problem definition process described in
the last article. What's next?
After the team has observed and
documented the process, a fishbone or
cause and effect diagram might be the
best next step. The fishbone
diagram is drawn to resemble the
skeleton of a fish, with the issue
(problem or process condition) on the
right side. The major cause categories
are written in the boxes on the left
side of Cause and Effect Diagram.
Summarize the major causes under the
categories. The basic categories are
usually people, methods, machines, and
materials. Sometimes, other categories
such as measurements and/or environment
are added. The step by step process is:
- Set up the fishbone diagram with
the categories on a whiteboard or
flip chart paper on a wall.
- Write down the problem on the
right hand side- at the head of the
- Hand out post-it notes to each
- Have each team member write down
the fcauses/factors observed about
the process that fall under the
- Discuss each cause or factor,
and work with the team to prioritize
these for further investigation.
After the fishbone is complete, we
want to verify/validate the causes we
have identified. This can be done
through further observation,
experimentation and/or data collection.
We want to investigate the causes to
identify which are the most important
causes. The best tool to
display this is the pareto chart, which
can be created after collecting data.
A pareto chart can be created using
Microsoft Excel, and the basic procedure
for creating one is as follows:
- Based on the fishbone, identify
categories with the team.
- Create an electronic or paper
form for data to be collected.
usually this can be accomplished
with a check sheet.
- Have some Collect relevant data
by category. For example, in
the pareto chart below, a check
sheet with causes for not meeting
the planned production for the day
was created, and the operators
checked off each occurrence in which
one of the failures occurred by
- After the data are collected,
Microsoft Excel can be used to
create the pareto chart. In
the newest versions of Excel, this
is a standard chart.
Once we understand and have verified
what the root cause or top contributing
causes are to our problem, we are ready
to begin identifying countermeasures.
We will talk about this in a future