Six Sigma 115
(B) Can you explain the fish Bone/ishikaWa diagram?
There are situations where we need to analyze what caused the failure or
problem in a project. The fish bone or Ishikawa diagram is one important
concept which can help you find the root cause of the problem. Fish bone
was conceptualized by Ishikawa, so in honor of its inventor, this concept was
named the Ishikawa diagram. Inputs to conduct a fish bone diagram come
from discussion and brainstorming with people involved in the project. The
following figure shows the structure of the Ishikawa diagram.
Figure 109 Step 4: Standard deviation
Figure 110 Fish bone/Ishikawa diagram
116 Software teSting interview QueStionS
The main bone is the problem which we need to address to know what
caused the failure. For instance, the following fish bone is constructed to find
what caused the project failure. To know this cause we have taken four main
bones as inputs: Finance, Process, People, and Tools. For instance, on the
people front there are many resignations ‡ this was caused because there was
no job satisfaction ‡ this was caused because the project was a maintenance
project. In the same way causes are analyzed on the Tools front also. In Tools
‡ No tools were used in the project ‡ because no resource had enough
knowledge of them ‡ this happened because of a lack of planning. In the
Process front the process was adhoc ‡ this was because of tight deadlines ‡
this was caused because marketing people over promised and did not negotiate
properly with the end customer.
Now once the diagram is drawn the end bones of the fish bone signify
the main cause of project failure. From the following diagram here’s a list of
No training was provided for the resources regarding tools.
Marketing people over promised the customer which lead to
Resources resigned because it’s a maintenance project.