AFAIK You cannot implement it by SImEvent's default blocks. What you need is a customized FIFO queue and is only possible using the MATLAB Discrete-Event System (MDES). This block allows you to programmatically define your customized queue.
Your MDES would need two input ports, two storages, and one output. Your customers (which are entities with two attributes of WaitingTime and EntryTime) arrive at the first storage and are stored in storage 1 which has a FIFO layout. Patience update events (entities) arrive at the second input port. They invoke an event to iterate over the existing entities in the storage 1 (using the method obj.eventIterate). You define an event action method for the iteration (say, CustomerIterate) which was invoked inside the obj.eventIterate and assign new values to the attribute WaitingTime. The new WaitingTime is calculated by subtracting the EntryTime from the current simulation time. In order to get the current simulation time, you need to create a simulink function which has a digital clock in it. You must declate this simulink function using the getSimulinkFunctionNamesImpl method.
