Definition (1):
Work specialization is dividing work activities into separate job tasks. Individual employees specialize in doing part of an activity rather than the entire activity in order to increase work output. It is also known as the division of labor.
Definition (2):
Work specialization allows managers to break down complex tasks into smaller more specific tasks that the workers or employees can complete. Every worker is trained specifically on how to perform a small, particular task in the best way. Gradually, that worker becomes extremely effective and proficient at doing that task. Thus, every worker in the company becomes an expert to some extent.
Work specialization is especially useful in manufacturing. Suppose an assembly process where every worker performs a repetitive task in the process of product development.
For instance, A assembles the frames, B fixes the sides, C paints the products, D assures that the products are complete, and E prepares the products for shipment. The whole development process is quite complex and is combined with different specialized steps. But this process becomes less complex when all the steps are divided among different employees. The products are completed and ready for sale after every employee finishes her/his respective task in the process of product development. If only one employee or worker were responsible for this whole process of product development, the outcomes would be much time consuming and less efficient.