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Re: [jwt-dev] JWT limitations?

Hi Francisco

At first I though your problem would require generating workflows on the fly (which will be considered this year in the wake of at least one research project using JWT). But now I believe you have to separate what should be handled at runtime by the workflow engine and what should be modelized at design time.

First, you don't have to "always start a new workflow from any step", but rather check wether a workflow corresponding to the same case (ex. the same truck, provided a given truck can't be at the same time in two different processes) as not already been started. This is done for example by looking in the current task list whether there is one that belongs to a process that has an id variable equals to this truck's id. Then you'll only create a new process if there is not already one. And if there is already one, you know which task should be done next.

Another solution could be to design the dependancies between all tasks in the JWT Workflow Editor (for example, before the Balance step, the Washing step should have been done) and then, for each task, replace it by a subprocess that checks in the right application of your SI wether it has been done yet and if not asks the assigned user (ex. the truck driver) to do it (this replacement could be done automatically with some code). This is only interesting if applications in your SI already track such information, and require to integrate them in the workflow engine.

I'm not sure about the "manager" and "checking wether a process can be started" part of your problem. It may either be answered with a validation framework, which JWT does not use yet (though it is built on the EMF technology, whose validation framework would therefore be a natural choice), or by letting managers change only the workflow state but not its behaviour (sequence of steps).

Finally, please note that JWT is mainly a tool suite, and that you must use your own workflow engine - though JWT supports some (like OW2 Bonita) and aims at easily supporting others.

Marc Dutoo
Open Wide
JWT co-lead

Francisco Suarez a écrit :
Good evening,
I'm writening from Patagonia, Argentina because I got stucked with a project. I would like to make a Java aplication with workflows that could determinate wether a process is able to be launched or not. I have several sub industrial process that must follow defined steps but the steps could change depending on the product. What happens is that somebody could launch a process at any time but I would like to know if JWT would analyse if all the previous steps were done. The intresting part of this is that anybody shoul be capable of trying to start any process at any time but still now I have only seen that JWT would limitate me to follow a certain secuence of steps always starting from the first one. For example, I have to procude corn oil so the trucks would arrive to my manufactures and would stop at the first barrier. If everithing is ok, it should go to a place where the truck is washed. Then it should go to a ballance to get it's weight, then to flush all the corn, then to the same or other ballance to be weight again, then to get paid and finally to the exit barrier. Now imagine that the truck driver goes from the firs barrier to the ballance and he didn't pass trhough the washing process, when the process of the ballance (written in any language or a peace of hardware equipment) is going to weight the truck that asks the truck id it must not allow the truck to be weight and it should inform the driver which steps were defined for the process and which steps he actually did. The idea of this is to be able to change the way things are done on an easy way for a manager that would't know how to write a single line of code and would only change the process secuence and everything must keep on working correctly with the new secuence.

If anyone knows how to solve this, please please please let me know!!!
Thanks in advance and sory for my poor English!!

Excelent project!!

Best wishies!!

Francisco Suarez


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