Twice during the last two weeks I found myself trapped in own neighborhood due to traffic snarls. You see I live on a hill right above a major intersection in northern Westchester County NY where Rte 35 the major East West route in the northern section of the county where the Saw Mill River Parkway ends and intersects with Interstate 684.
What happened the other week was a freezing rain caught weekend Christmas shopping traffic and the highway departments off guard . Two accidents on Rte 35 just to the west of me managed to shut down traffic everywhere so I could even get out on to 35 to head the other direction and a week later an accident somewhere to the north out of site to me shutdown north bound traffic on I684 and cars and trucks trying to bypass the stoppage then backed up and clogged traffic on Rte 35 as they tried to skirt over to nearby Rte’s 22 and 100.
This all got me thinking about project management.
I have a saying I often use that is:
“It only takes a day to fall a week behind”
The funny thing is (or maybe it not so funny) I find I can often find circumstances where I can reframe that expression as:
“It only takes and hour to fall a week behind”
“It only takes a day to fall a month behind”
All this reminded me of a kool traffic simulation tool that I discovered back in March of 2008 while reading Grist which I then posted to the Yahoo CMSIG Group I follow.
The java based traffic simulator you can find over here: Dynamic Traffic Simulation
…and the Grist article also had this neat YouTube video from New Scientist Magazine showing a real life experiment conducted by some Japanese researchers showing how some traffic jams can occur for no apparent reason at all.
Lawrence Leach (the author of the excellent book Critcal Chain Project Management) then replied (the emphasis is mine):
How cool is that! Thanks.
My mind naturally wanders toward using it for learning about
projects. In some ways I think it might be more valuable than dynamic
Monte Carlo simultions; particularly to help thinking about multiple
projects. I have run such simulations, and get a blah response. Maybe
this works better because we can really relate to traffic flow.
I don’t know yet how well this metaphor works, but I naturally
thought of the vehicles as tasks on a project, and the two main lanes
as the critical chains for two projects flowing along. The on-ramp
represents feeding chains of tasks, of course.
One of the first things to catch my eye was how tie-ups flow upstream
against the flow. Its like problems near the end of one project, or
even on projects released to the field, impacting earlier work on
I didn’t fool with it, but one apparantly can show the effect of
queueing, and relate that to capacity buffer sizing.
I think there might be much more to learn from this simple dynamic
simulation. Other thoughts on it?
And again a few days later commented again (again the emphasis is mine):
I have been playing a little with the traffic simulation. I already
think there are some great messages one can put across from it.
BTW, I got the English download through the author, If he didn’t put
it on the original site, let me kwow and I will provide another link.
One of the first things I liked with the basic simulation is that it
shows how the traffic jam flows upstream from the merge point. If we
consider the merge the actual constraint, it means “the pile” can be
well upstream of it.
I also found that when you decrease the inflow, it takes a long time
for the jam to clear. The jam clears from the “front end” forward,
which would look like a moving constraint.
If you throttle in inflow, the system is insensitive to ramp flow,
once the ramp is clear and the oncommers can merge, rather than have
Overall, it shows the power of dynamic simulation to understand
reality, as compared to the TOC over-simplificaition. It shows most
of the TOC statements reflect a subtle pseudo steady-flow assumption.
(OK, I am prepared to hear the screams of “not so!” on this, but its
I think there is much more to show. I am sure it will show the non-
linearity of queuing, for example.
This all has me thinking again about project management as I drive around and run into holiday traffic and grid lock. Thinking what lessons relative to project magement can I learn from this jam I am in sure beats the stress and anger that some people let get their goat.