REPLY Models, Problems and Systems (SD6997)

[SDMAIL Jean-Jacques Laublé]

Posted by  Jean-Jacques Laublé <jean-jacques.lauble at wanadoo.fr>

Hi Kim

I have a different understanding of the mantra :
model the problem and not the system.

Of course some years ago, I did not understand
this the same way I understand it to day from the
lessons of experience.

I try strictly to model a problem and not a system
because I set a clear objective to my model: solve the
problem or answer a precise question that will alleviate it.

I will after my modelling effort, be able to compare the results
obtained with the initial objective.

If I model a system, there is no clear objective and only a vague
hope that something positive might come out of it.

Modelling the problem is too much simpler and less pretentious.

Of course I do not deny that the scope of that way of working is
limited and that it can generate limited policies but I think that
it has the great advantage of being simpler and quicker to model and
it is always possible to change the model later on or make another one
once there is a first understanding although eventually limited of the
whole system.

Another reason of working toward a problem and not a system is that
a system is difficult to define, entailing a lack of rigour when defining it.

On the contrary a problem may be much more precisely defined at the
beginning.
Regards.
Jean-Jacques Laublé Eurli Allocar
Strasbourg France
Posted by  Jean-Jacques Laublé <jean-jacques.lauble at wanadoo.fr>
posting date  Wed, 7 May 2008 15:39:21 +0200