Shell Programming and Scripting

Hi,
I am a shell script which takes input parameters and performs various functions. My concern is, if we call the same shell script with different parameter values from different sessions, will the results be inconsistent?
Are there any precautions I need to take inorder to avoid conflicts between several instances of the same script?
Is there any limitation on the number of parallel instances you can create for a shell script?
BTW, I am using bash.

Thanks

The one practice in I can think of is that any temporary files you store in /tmp or /var/tmp should use $$ (the current processes PID) as part of the filename to avoid clashing file usage. Doing this means it is important to remember to delete the temporary files when you have finished using them or else /tmp will get clogged up!

Any outputted results file should either use $$ or the date and time in the filename to avoid them clashing or else make sure you append to the output file (>> outputfile) not replace (> outputfile) which would overwrite the previously run script's results.

Multiple runs of a script with different parameters should not be a problem otherwise.