Final answer:
During the 'mass production' era, operations management primarily focused on production and design, leading to more efficient and speedy production of finished goods.
Step-by-step explanation:
During the 'mass production' era, operations management primarily focused on production and design. This era was characterized by a mechanized work environment and a focus on producing identical products in every location. Workers were trained to complete one or two steps in the manufacturing process, leading to more efficient and speedy production of finished goods. However, it's important to note that sales also played a role in operations management during this era.