schedulers for laboratory automation

A scheduler is a simple and easy-to-use way to get different instruments to work together in a coherent and structured manner.

When a process is performed manually, the operator links the plate from storage or fridge, moves the plates between pipetting step and plate reader step all logically and almost in an unthinking manner.

When a robot or stacker is used to pass the plate around the process, a control environment is required, and this is where the scheduler program is used.

The current thinking is that there are 3 types of schedulers, paa supply two of these three types of scheduler.

• event-driven or real-time schedulers
• static, pre-emptive and time driven schedulers
• dynamic, pre-emptive and time driven schedulers

These are described below in more detail. In our experience, some manufacturers offer one scheduler dynamic, pre-emptive and time driven to give the flexibility of event-driven and time driven schedulers. However, paa believe that the best solution is to offer pure examples of each type of scheduler.

With a real-time/event-driven scheduler, the system will run 'flat out' with little or no control of timings (although Overlord3 in event-driven mode does support key timing for one process). There is resource sharing but little or no resource planning, so if a resource is required the process has to wait until the resource is released. Uses include; simple processes such as plate processing through devices such as plate reader or plate.

paa have Overlord3 in the is category of schedulers.
Overlord3 real-time/event-driven scheduler ...

With a pre-emptive scheduler, the system runs to a planned time schedule, with total control of the time windows for each element in the system. There is resource sharing and there will never be any conflict in the use in the system resource (unless there is an error, when under certain circumstances the time windows will shift). Uses include; cell culture and processing.

The strength of this type of schedule is the guarantee of samples being treated in an identical way. There is little scone for decisions in the schedule. A pre-emptive is TIME driven.

paa have Overlord3 in this category of schedulers.

Overlord3 time resolved/static/dynamic/pre-emptive scheduler ...