conscientious
adjective
uk/ˌkɒnʃiˈenʃəs/ usserious about your work and putting a lot of effort into doing it in a careful way:
Greg Smith is a conscientious and dedicated worker who will be an asset to your company.
conscientiously
adverb
Employees are expected to carry out their duties conscientiously.
conscientiousness
noun [ U ]
The study examines the relationship between conscientiousness and flexibility, and their effect on performance.