The S/D boundary rule

The S/D boundary rule is the test that tells you whether a stuck problem is a System problem (who or what carries the work, through what handoffs and checks) or a Destination problem (what outcome counts as better, and who has the right to decide). Ask whether everyone would call the same result a win. If yes, compare carriers. If no, stop comparing and settle the goal.

Three siblings, one group text, six weeks of it. Your father is 82 and should not be driving himself to dialysis anymore. Your sister wants a paid aide four mornings a week. Your brother says he can rearrange his Tuesdays. You price out a van service and send screenshots. The thread stalls and restarts, and every round looks like it is about calendars. But your sister keeps saying "safe" and your brother keeps saying "home," and nobody has noticed those are two different goals.

Ask one question out loud: if this plan worked perfectly, would all three of you call the same result a win? If yes, you are in System. Line up the aide, your brother's Tuesdays, and the van service against cost, what happens when a carrier gets the flu, who notices within an hour if a ride is missed, and where the medication list lives at each handoff. Choosing those criteria is part of the job, not a detour from it. If no, stop comparing. One of you means independence, one means never falling again, and no schedule reconciles those. The loop ends the moment you name it, because the loop was two people answering different questions. When both are genuinely contested at once, settle the destination first, or every carrier you pick gets relitigated the day it costs someone something.