question

Rahul
Neither excel nor minitab are measurement tools. Minitab is a statistical analysis tool and excel, of course you know, is a spreadsheet tool with sophisticated statistical and numerical capability.
If your question is more about what is a good data recording tool, excel (or word table) is a good choice. For analysis, I would use minitab, but for the calculations you are trying to perform, excel should be easier as they are simple arithmetic.

Rahul
If in your situation, I would start with a histogram or a scatter diagram unless I am examining trend. A histogram would give you a view of variation in your process output for the sample. See what % of your process output meets the specs.
Now to see the performance on a time dimension you can do run charts or any other control charts that help you see the trends.
Further, I am not sure if you have data about potential Xs, if you do, you would conduct hypothesis testing to identify causal relationships.
Of course, this is a very high level, simplistic view. But tread down this path and ask specific questions about the tools if you run into issues.