Set a fair starting point for the trial
Before the first Wednesday pickup, record roughly how long the usual grocery trip takes, who plans the list, and what problem you want to improve. A family trying to reclaim an evening should include ordering and unpacking in the comparison. A family trying to avoid carrying heavy bags should measure whether pickup actually removes that part. The same trial can produce different results depending on what the household needed to learn.
Measure the whole change, not just time at the store
Pick a useful measure before starting. Did pickup reduce the total time spent, including ordering and waiting? Were important items missing? At the review, decide whether to keep, adjust, or stop the arrangement. The trial should not continue by accident when the review is missed.
Give the trial a decision date and an exit
In week one, note whether orders were ready when promised. In week two, look at missing or substituted items and any extra shopping trip. In week three, ask both the list maker and collector whether the new method helped. If only the collection day failed, try another day before abandoning the idea. If the underlying burden simply moved to another person, stop or redesign the arrangement rather than calling a completed trial a successful one.