Lookup / Option Set / Global Option Set – When to use what ?

Lookup:

Lookups is Dynamics 365 involves an entity. If there is a scenario where the users need to update the list of elements on their own very frequently and they don’t require a developer to be involved, lookup is the best option to consider.

Secondly, if the list of elements is a lengthy one and a scroll bar starts appearing (more than 10 elements normally), it looks unpleasant in terms of User Experience so it is suggested to use lookup in such cases.

While using lookup, you need to be extra careful when importing/exporting records. Make sure the GUIDs don’t change when you are migrating the records to other environments.

Option Set:

Option Set is favourable for conditions where the list of elements rarely change. So the developer can set it once and it can be used forever.

Also, when there is a multi lingual scenario, and translation is involved, it is much easier to translate labels of the option set items.

Global Option Set

Global Option Set is considered when the list of elements can be re-used across multiple entities.