The article is devoted to the development of a classification of tasks $Z=(P,R,W,F)$ of finding the timetable of one device with the given parameters. Each of the tasks has a positive weight $w_{i} \in W$, processing time $p_{i} \in P$, and waiting time $r_{i} \in R$, if it is not available for the service, and a given criterion F of optimal schedule. The possibility of a scheduling polynomial in the time for these tasks is shown. It is proved that the optimal solution of the tasks of scheduling a device is the nondecreasing ordering $\sigma =(i_{1},\ldots,i_{k} )$ of the elements of permutations $X=(r_{i_{1}},\ldots,r_{i_{k}})\in E_{kn} (R)$, $R$ is a multiset of waiting times of tasks.