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Sustainability Impact Assessment

Score an architecture proposal against environmental sustainability criteria so carbon and energy impact are part of the decision record, not an afterthought.

Phase D, Technology ArchitectureDerived from TOGAF

Sustainable IS decision matrix: business value against carbon intensity on two axes

The grid pairs business value on the vertical axis against carbon intensity on the horizontal. Each quadrant names the action the combination demands, from scale to retire.

Sustainability is a trade-off, not a slogan. The matrix exposes which workloads are worth their carbon and which are not, so the portfolio is triaged on evidence rather than sentiment.

Sustainable IS decision matrix: business value against carbon intensity on two axes A two-by-two matrix of sustainable IS choices on two blue axis rails: a vertical Business value rail, low to high, and a horizontal Carbon intensity rail, low to high. Each quadrant names the action for one combination, with a green marker for the gain and an amber marker for the carbon move it implies. High value and low carbon is Scale, the easy win. High value and high carbon is Optimise: worth keeping, so reschedule, right-size and refactor. Low value and low carbon is Leave but watch. Low value and high carbon is Retire or relocate to a greener region. A red note marks the high-value high-carbon workload as the one to optimise: too valuable to retire, too carbon-heavy to scale. Business value: low to high Carbon intensity: low to high High value, low carbon Scale The easy win Grow within the carbon budget High value, high carbon Optimise Worth keeping Reschedule, right-size, refactor Low value, low carbon Leave but watch No urgency Re-check yearly Low value, high carbon Retire or relocate Free up the budget Move to a greener region or stop What the combination gainsThe carbon move it implies High value and high carbon is the workload to optimise.It is too valuable to retire and too carbon-heavy to scale, so it earns the engineering effort toreschedule, right-size and refactor.