Final answer:
Measurement of productivity is not a significant difference between manufacturing and service operations because both sectors strive to enhance productivity, despite using different metrics and approaches.
Step-by-step explanation:
The question seeks to identify which aspect is not a significant difference between manufacturing and service operations. Among the given options, Measurement of productivity is not a significant difference because both sectors focus on optimizing productivity, albeit through different metrics and methods. Cost per unit and Uniformity of output are more aligned with manufacturing due to the tangible nature of goods and the replication in mass-production. Labour content of jobs and Amount of customer contact generally lean towards services, which are often labor-intensive and involve direct customer interactions. Thus, while manufacturing and services may measure productivity differently, the emphasis on improving productivity is a commonality between the two.