Fairfax county has implemented a ban on plastic grocery bags, or maybe it's plastic bags from shops? Anyway, we've invested in a nylon bag for me to use when I'm buying a few items, often during a walk, and a set of 3 foldable bags with cloth sides for the weekly Friday shopping.
But this change which seems so simple turns out to be a bit more complicated. When I'm shopping, I use the self-checkout station. It's designed so you identify/weigh each item you're buying, then place it into the plastic shopping bag above the scale. That works well. But when I try to replace the plastic bag with my nylon bag, the system detects the weight of the nylon bag and commands me to remove it. So instead of placing the id'ed items directly into the bag, it becomes two steps--one onto the scale, then after I've paid the bill, moving the items from the scale to the nylon bag.
Using the foldable bags reveals a separate problem--they're designed to fit within the shopping cart, which is fine, but that means they're just a bit too big to fit onto the stand where the checker has her plastic shopping bags, meaning it's awkward for the checker to fill the bags.
My poin is this is symptomatic of many changes--because things are designed as a system, or they evolve into a system (which I think is the case with groceries) of interrelated parts. A change in one part of a system will require changes in other parts.