There exists no supportive team quota of power grid overhaul & operation and maintenance in China power industry. Based on production workload assessment which power supply enterprise needs, it is necessary to carry out the team workload assessment method so as to entrust a reasonable workload of production business. This paper considers the specific process of tasks as the smallest unit modules, estimates manual consumption of each process for overhaul, testing, operation and maintenance and class work in reason to form a team quota. And combining equipment account information, this paper applies team quota, designs workload assessment algorithms, statistics substation and transmission production business workload yearly, and carries out reasonable workload analysis of the relay team, a main transformer protection eliminating defects project is used as a specific example. This example shows that the method can provide a tool for power supply enterprises with gathering the completed production business workload yearly, assessing the proportion of entrustment, and forecasting production business workload.