Tuesday, October 13, 2020

Coupling, coherence, and other stuff



Has someone in your PMO suggested applying a dose of system engineering to portfolio management? If they have, I wonder if they think of it as "three C's and D"?

A bit cryptic? Well, not so much when you spell it out:
Coupling, coherence, cohesion, and diversification

The short form explanation of  three C's and D looks like this:

Here's a little explanation:

Coherence

Coherence is what gives rise to reinforcement and to synergies. Coherence gets its power from phasing and sequencing....in other words, timing. Take 20 people and let them chat at a party and you have--to the macro listener--noise; but phase things correctly and you could have a choir. In other words, from noise a song!

Cohesion

Cohesion is what makes things stick together and perform under stress; to accept tension among parts and keep on going. In a portfolio, it's a matter of making good on the overall business value proposition, and doing so under stress.

The qualitative idea is weak or strong cohesion; ordinarily the metric is strength under stress, which for projects is tolerance for failure.

Strong cohesion means that if one project, or some aspect of a project, fails in some sense, the tensions created among projects because of failed dependencies are not crippling to the business outcomes. Cohesion requires redundant or alternate paths to customer satisfaction through the network of portfolio projects.

Coupling

Coupling is well understood notionally: it's the idea that one effect or outcome directly influences another. Generally, we think of coupling as being loose or tight, referring to how well one effect is transferred onward. Insulation loosens the coupling between outside and inside, etc. 
 
In projects, loose coupling is usually the desired quality. A failure in one project is not coupled into the next is the idea. In portfolios, the same is true. We want high coherence and strong cohesion but loose coupling. And, all three together is sometimes a challenge.

Diversification


Most of us understand diversification from the financial portfolio experience: when one investment is down, another is up, and the overall result is within a range of acceptability. If all investments are really independent of each other, the range of results is compressed by approximately the square root of the number of investments in the portfolio--the square root of N rule.

The same is true of project portfolios. The secret sauce is independence. If coupling is not loose, independence is forfeited, and so also is the power of diversification forfeited.

How to sum up?

Perhaps I'll just say there's a place for system engineering in project management. 




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