use of commas

Grammarly's handbook has an extensive section about the comma.

http://www.grammarly.com/handbook/punctuation/comma/

First of all, analysing these objectives is a subordinate clause, meaning it wouldn't stand as a complete sentence on it's own. These are set of by commas. When is a subordinate conjunction.

A lesson in conjunctions seems relevant here. Conjunctions join words, phrases, or sentences together. We are most familiar with coordinating conjunctions like and, but, or (there are more, but these are the most popular). Coordinating conjunctions join sentence elements that have equal weight, meaning both elements could be a sentence on their own. Subordinate conjuntions (when, where, after, although) join subordinate clauses to main clauses.

Another part of your sentence that needs to be looked at is your use of which in which should be dealt with.  Which is a relative pronoun that is to be used when the information that follows it isn't intergral to the meaning of the sentence. Basically, when the information could be taken out of the sentence and the meaning of the sentence would stay in tact. In this case, you needed to use that, which is used when the information following it is critical to the meaning of the sentence.

Here's how your sentence should read:

When analysing these objectives, there are several aspects that should be dealt with.

1. "The Grammar Reference Guide" 2nd ed from CareerTrack

2. http://grammar.quickanddirtytips.com/which-versus-that.aspx