Am I Done with My SOA?

For those building SOAs in their organization…how do they know when to stop, or slow down? I mean, you can service enable and orchestrate the entire enterprise, perhaps your supply chains as well, but I doubt the cost of doing that is going to justify the benefits on most cases. However, clearly you can do to little, and thus not get the benefits you need. You need to find a balance.

So, we are assuming that there comes a time in the implementation of a SOA when the effort has a diminishing return or the point when the amount of effort won't produce enough value to justify continued work at the same level of effort. So, how do you figure that out?

So, consider the amount of effort over time as EOT, and the value of agility as VA and the value of reuse as VR. We're assuming that VA and VR change as EOT changes, over time, the trick is to determine the degree of change, or relative value, and how that relates to EOT over time.

Thus,

Relative Value = (EOT * (VA + VR)

As an example, let's say that EOT is a constant 25 percent of resources, typically as to how SOA projects work. Furthermore, we're assuming that VA diminishes by 10 percent yearly and VR diminishes by 5 percent yearly…again, back to my ROI article.

Thus,

Year        EOT    VA        VR            RV

1        0.25%    90        95            0.4625

2        0.25%    81        90.25            0.428125

3        0.25%    72.9        85.7375        0.39659375

4        0.25%    65.61        81.450625        0.367651563

5        0.25%    59.049        77.37809375        0.341067734

6        0.25%    53.1441    73.50918906        0.316633223

7        0.25%    47.82969    69.83372961        0.294158549

8        0.25%    43.046721    66.34204313        0.27347191

9        0.25%    38.7420489    63.02494097        0.254417475

10        0.25%    34.86784401    59.87369392        0.236853845

11        0.25%    31.38105961    56.88000923        0.220652672

12        0.25%    28.24295365    54.03600877        0.205697406

So, it looks like year 5 or 6 is the time when it makes sense to ramp down the efforts, else suffer diminishing return. Once again, just a set of data points to assist you in making a decision.

Posted by Dave Linthicum on July 17, 2007 02:32 PM