Fig. 7 Cause & Effect diagram for low SAW Boom machine welding process yield
Why-Why analysis
Fig. (8) shows a why-why diagram which helped in identifying root cause of the problem.
Failure Mode and Effects Analysis (FMEA)
The major causes, prioritized on the basis of RPN, are porosity, drifting of job while welding, slag, lack of fusion, improper control of process parameters, etc.; which are responsible for low yield of the welding process.