As promised, I am now making my ILM_Scheduler service source code available for download.
In brief, the notion is to optimise ILM/MIIS scheduling through the use of a queue. You add jobs to the queue and they are executed, one at a time, and in order of priority. You can schedule a job by adding it to the queue at a particular time, or you could have other processes (database triggers, other applications) that add jobs to the queue as and when needed.
Please be aware that this is not a ready-made system – you will have to create your own VB project and compile the service. You may also need to make changes to suit your environment, but hopefully this code will provide a good starting point.
You will also find a few vbscripts to assist with adding jobs to the queue and checking the queue.