Properly using and maintaining starter cultures is crucial to producing consistently good cheese.
Culture selection, use, distribution, monitoring, implementing and maintaining a rotation program plus technical support from your supplier are all very important aspects to keep in mind.
Other factors that can determine the type of starter culture to use can be proteolytic activity, salt sensitivity, acid development, culture format i.e. single strain / defined multiple strains, freeze dried direct vat inoculum, frozen direct vat inoculum, bulk cultures.
A serious challenge also comes in the form of bacteriophage contamination - refer to the article available on the importance of starter culture rotation.
** Refer to the article attached for more information on how to decide which type of starter culture would be best to use for your specific circumstances.