will Upgraging ESS business package from 1.41 to 1.51 will mess up the application using from old version

Hello guys,

We are planning to upgrade old our ESS business package 1.41 which is deployed on SAP netweaver 7.01 to BPESS1.51. But we are already running with appraisal process which is running fine with 1.41. we don't want to mess up the appraisal process which  is running fine with older version ie 1.41. But now, we need some of functionality for leave applications which are only available on BPESS1.51. So now my question is deploying newer version of business package disturb other applications which are already running fine on older version??

Please provide your valuable inputs.

-Ajay