Question : I did not understand what does the transaction percentile value mean in the ? And what is the best option to set the percentage value so that I can exclude the think time from the total scenario time
This value tells you that n% of all transactions samples had response time lower or equal to that value. The higher the percentile is, the closer you get to the maximum response time value. Average transaction response time value may be misleading since standard deviation can be very high.
Let's see an example. Let's assume the following response time samples for a specific tramsaction: 2, 2, 2, 20, 20, 20, 20, 24, 28, 30.
The average value of this series is: ~17
The 90th percentile is ~28
From this series it is clear that it is more likely a user will get response higher than the average response time. The 50th percentile, also known as median, will yield a more realistic number.
90th percentile is often used as a target when setting performance objectives. This is a more rigorous target to set than average.
Regarding your second part of the question....
> Percentage value that appears in the Summary Report can be configured in the General tab of Analysis Tools > Options dialog
> Excluding think time globally from all the Analysis Session can be done from Global Filter filter dialog which is available from Analysis File menu
Please note that LoadRunner 11.00 comes with Percentile SLA feature that can help measuring performance objectives. It also comes with more flexible percentile settings in the new reports introduced in Analysis 11.00
