RE: [SAGE] INCOSE

["John LLOYD" <jal@mdacorporation.com>]

I'm a member (#7468), and also one of those degreed engineers who does real (INCOSE-style) system engineering.


> [***back to Stephen***]
> That looks representative of their applicability: much of it applies
> (e.g., "Document everything."), but significant pieces don't.
> 
> Also, part of the systems engineering approach is to model solutions
> before building them, but in the case of computer system 
> administration,
> it is often more expensive to model a system (representation +
> instrumentation + interpretation + measurement) than to build 
> it.  I do
> hope that virtualization techniques (e.g., Solaris domains, 
> VMware, Xen)
> will begin to give us the tools to do cost-effective modeling.
> 
>     - Stephen
> 


Don't confuse "modelling" with "building a small-ish version of the system", which is more properly called a prototype.

System engineers make math models, out of Mathcad, Excel, system models out of pencil and paper, and other models as mental exercises.  There are models to describe the problem (hence you get "context diagrams", or models, showing the system and the important things it interacts with). There are functional models (input this, output that), performance models (output that just this fast), and so on.  

I think the issue for the unpersuaded is that INCOSE uses certain terminology that does not match system-admin terminology, or uses certain methods that system admins either do unconsciously or not at all.  "Modelling" is one example -- when somebody asks you to build a system with X terabytes of disk you automatically think about what your "best" answer is, and why.  System engineering is just that plus writing it down.

System engineering methods, when suitably tailored for the problem at hand, are efficient (because they are tailored to be), and most importantly aim at solving exactly the given problem, and no more and no less.   That is the value.  


--John