When doing nothing is something. How task allocation strategies compromise between flexibility, efficiency, and inactive agents

We expect that human organizations and cooperative animal groups should be optimized for collective performance. This often involves the allocation of different individuals to different tasks. Social insect colonies are a prime example of cooperative animal groups that display sophisticated mechanisms of task allocation. Here we discuss which task allocation strategies may be adapted to which environmental and social conditions. Effective and robust task allocation is a hard problem, and in many biological and engineered complex systems is solved in a decentralized manner: human organizations may benefit from insights into what makes decentralized strategies of group organization effective. In addition, we often find considerable variation among individuals in how much work they appear to contribute, despite the fact that individual selfishness in social insects is low and optimization occurs largely at the group level. We review possible explanations for uneven workloads among workers, including limitations on individual information collection or constraints of task allocation efficiency, such as when there is a mismatch between the frequency of fluctuations in demand for work and the speed at which workers can be reallocated. These processes are likely to apply to any system in which worker agents are allocated to tasks with fluctuating demand, and should therefore be instructive to understanding optimal task allocation and inactive workers in any distributed system. Some of these processes imply that a certain proportion of inactive workers can be an adaptive strategy for collective organization.