Dear All,

My name is Bharathi Rajan, working in Tolaram group, Nigeria. I am currently doing six sigma project here. My project is on reduction of downtime for which I have collected my historical data from ERP for the year 2010. But to validate that data and calculate financial benefits, I need to collect baseline data. Please help me on deciding the sample size for the baseline data.

Note :

The factory is running 6 days a week 3 shifts a day.What will I have to take as a sample (per day, per shift,per week,per hour) since my Y is percentage of downtime.

Thank you,

BHARATHI RAJAN.

Interesting and very valid question. Subject matter experts may like to decide what is a good sub-grouping logic in the process. If hourly sub groups provide big between group variation (as compared to within group variation), then it should be taken as hourly.

More comments welcome.