REPLY Process, cost and quality (SD6105)

[Bill Harris bill_harris facilitatedsystems.com]

Posted by  Bill Harris <bill_harris at facilitatedsystems.com>

>> Doing background research it seems that system dynamics ticks all the 
>> right boxes, but before going down a learning path wanted confidence I 
>> was in the right ball park.


I'd give you two cautions.  First, system dynamics is usually used to
solve a problem, not to model a system, for it's hard to know when to
stop modeling if you want to create a model that can answer any question
you throw at it.  So, if you have a particular issue that concerns you
in project planning, system dynamics may be a great tool to help you
make sense of it and figure out a way to reduce or eliminate it.  If you
need a system to which you can tell the characteristics of a project and
have it spew out the decisions you need to take (as you might do with a
linear programming system), I think you have a harder job.

Second, system dynamics is a tool for making sense of feedback systems,
and feedback requires a certain amount of time to engage.  If you aren't
concerned with the effects of feedback on your projects, you may not be
as interested in this as some other approach (queueing simulations, for
example, dynamic programming, or so-called "discrete event
simulations").  That said, you might look at the classic _Introduction
to System Dynamics Modeling with Dynamo_ by George Richardson and
Alexander Pugh.  That book uses a project management problem as the
example for its introduction of system dynamics, focusing on the
problems caused by an accumulation of unrecognized but needed rework.

As you can see from the example in that book, the essence of the system
dynamics contribution was in uncovering the impact of the accumulation
of such hidden future rework.  Such a model likely is best used to help
you see that you need to pay attention to that accumulation of future
rework if you want to avoid end-of-project surprises.  Without creating
a significantly more complex model and then testing and calibrating it
well (think increased cost and time), that model may not be as useful in
telling you that the cost of the rework is £3.52 for each £1.00 you save
in upfront project reviews and thus picking the exact investment you
should make in each part of the process to maximize your profit, for
example. 


>> Hope I have provided enough info.


I've probably sounded a bit pessimistic; I don't mean to.  Now that you
hear what I've said, I'd be curious to hear more about your goals for
such a system.  Precisely what sort of questions do you want to answer
using this tool?

Bill
-- Bill Harris
Facilitated Systems
Posted by  Bill Harris <bill_harris at facilitatedsystems.com>
posting date  Wed, 13 Dec 2006 15:47:51 -0800