This commitment ensures when there is an opportunity to improve on our members’ quality of life, we have the information needed
closed as general reference by RegDwighт♦ Jan 18 at 18:12
This question is too basic; it can be definitively and permanently answered by a single link to a standard internet reference source designed specifically to find that type of information. See the FAQ for guidance on how to improve it.
yes, it is the quality of life that belongs to (plural) members, thus an s' is proper.
Yes, you use an apostrophe after the S.
(I was previously remembering wrong above. The case that some guides disagree with my taste on is when there is an apostrophe following a word that ends in S for another reason - some use s', some s's and some have more complicated rules - so you can have e.g. boss' in some guides and boss's in others. I was mis-remembering which ways some of them disagree with me).
The sentence should perhaps though be:
This adds a that, and changes "improves on" to "improves". The idiom "improves on" means to do better in another case. You don't want to make somebody's quality of life better than your members', you want to make your members' quality of life better.
You're referring to a noun (quality of life) possessed by more than one member, so yes, it should read "members'".
I'd like to suggest revising the statement to something like, "(Name of person, group, company, etc. as a possessive...) commitment to X ensures we have the needed information to improve our members' quality of life at every opportunity."
For example: "Green Hills Nursing Home's commitment to digital record keeping ensures we have the needed information to improve our members' quality of life at every opportunity."