1. Unions quite frequently oppose the time study because the accuracy of time study is overly dependent upon the skill and judgment of the time study man. The time engineer must be well drained and they should have both the background and experience in conducting time study of course to reduce the area of human judgment the time study engineer may employ work sampling technique.
2. Time study is not suitable for non repetitive jobs ( it is also not suitable for non standardized or indirect labor jobs)
3. If an output standard is unattainable it subverts effective performance by lowering operator morale due to the offered but unfulfilled inventive.
4. It is less suitable on jobs paced by automatic machines than on jobs where operator s control the work pace.
5. Coupled to incentive wages output standards may contribute to under emphasis on the quality of production.
6. Mechanical physiological psychological and sociological sources of variation may effete the output and quality performance of workers adversely. This could definitely upset the successful applications of time study based output standards.