we have deployed package or task sequence into static or dynamic collection with always re-run or re-occurrence re-run settings . issue is need to replace sourcefile small or big change in source file setps need to perform stop advertisement and replace new content update source version (update package) re-enable advertisement. now question is if machines are already received old policy how they behaves and if machines already installed package\task sequence how they behaves.

The deployment will fail if the policy wasn't updated on the client, yet, because it will try to locate the old content. As soon as the policy is updated on the client, the client will successfully download the updated content an run.

Peter is correct, however I think the crux of the question is what will the client do when the source files are updated in relation to existing deployments. The answer is nothing. Source file changes do *not* trigger deployments to be rerun. If the deployment has not run yet, as Peter noted, the new files will get downloaded, however, if the deployment has already been enforced, there's nothing to be done as the point of the deployment to run the appropriate command-line. Once that's been done, a source file change is meaninglessness.