You need a Resource Acquirer block, two Entity Server blocks, and two Resource Release blocks. When the entity enters the Resource acquirer, it acquires resources from both tasks. Then the entity enters into the first server, which is the one with the smaller service time. Next, it is forwarded to the first resource releaser, where the resources for the task with smaller service time is released. Then the entity enters into the second server, where it will be delayed for the REMAINING serivce time of the task with the larger service time. Finally, it enters the second resource releaser, where it relinquieshes the other acquired resource.