Strategy
Part of A store conversion plan built on a defined journey and predeclared stop rules
Ninety days to a reversible store change, with the dates owned by the buyer
Sequence a reversible ninety-day store conversion decision with buyer-owned dates, safe evidence gates, controlled comparison and tested rollback.
What to take away
- Run one reversible change at a time, against a frozen baseline, and let the buyer set every calendar date.
- Hold each stage at a named gate until evidence, a responsible owner and a rollback path all exist.
- Treat an observed rate change as a claim to be evidenced rather than a result, until a counterfactual supports it.
- Give each specialist reviewer a separate sign-off, because one approval cannot cover consumer law, privacy, safety and payment risk.
An illustrative ninety-day calendar
The ninety-day span is a sequencing template. The buyer writes the real dates, and those dates move whenever a gate has not cleared. The span itself says nothing about whether a store has enough traffic for the decision it wants to make.
| Stage | Template window | Gate holds until |
|---|---|---|
| Establish the current journey | buyer-set days 1 to 10 | seller identity, journey ownership and a safe baseline are confirmed |
| Inspect customers and controls | buyer-set days 11 to 25 | no current or proposed route misleads, excludes or reaches an unsafe transaction |
| Choose a reversible option | buyer-set days 26 to 45 | every specialist owner accepts the evidence inside their own scope |
| Prepare the comparison | buyer-set days 46 to 70 | allocation, exposure and guardrails can be verified |
| Release, decide or hold | buyer-set days 71 to 90 | stop signals are monitored and the previous version is recoverable |
A blank cell in that table is a normal state, not a failure. The store-change budget template puts a source field on every row, which suits a change whose costs are still estimates.
Example: a reversible checkout change and its gate criteria
An England homeware retailer requires account creation before payment. The proposed alternative adds a guest route beside it, with identical prices, delivery promise and returns terms.
- Freeze the current checkout and record the journey map, the measurement definitions and the price, delivery and returns copy.
- Add a guest option that asks only for the fields needed to take payment and deliver the order, leaving the account route live.
- Clear the gatethe privacy reviewer checks the marketing checkbox against the ICO guide to PECR, the accessibility reviewer tests labels and error handling, and the payments, safety and security owners accept the change.
- Keep the previous checkout deployable, then confirm that orders, refunds and cancellations survive a rollback.
Reversibility means the previous version can be restored inside the buyer's own recovery window without losing an order, a refund or an audit record.
If a supplier builds the guest route, the conversion supplier contract questions cover exit, data return and rollback, so nobody negotiates those after launch.
What evidence supports a causal claim
An observed rate change is not customer benefit, retained revenue or a causal result unless evidence supports that statement. The claim needs a counterfactual, not a before-and-after chart.
Evidence that would support causality: the two routes ran in the same period for the same population. No other checkout, price or campaign change was live. Late orders, refunds and cancellations were assigned to the period they belonged to.
If the gain appears only where a free-delivery banner also ran, the causal claim fails.
HM Treasury's Magenta Book sets the same discipline for policy evaluation: monitor outcomes, but never read causality from them without a credible comparison group. Compare the options with attribution methods compared before committing to one.
Who signs off each gate
Each gate belongs to a named reviewer, and no reviewer can clear another's scope.
- Consumer and pricing reviewerthe CMA's Price transparency guidance (CMA209) and the Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013.
- Privacy reviewerthe ICO guidance on storage and access technologies, plus the PECR marketing rules.
- Accessibility reviewerWCAG 2.2 labels, error handling and input design.
- Safety and security reviewersOPSS product safety advice for businesses, plus NCSC guidance on secure online services.
- Statistics and experimentation reviewerallocation, exposure, missing data and the credibility of the counterfactual.
During release, watch consumer, accessibility, safety, privacy, payment and security stop signals. The NCSC guidance on building and operating a secure online service covers access control, logging and incident response for the window when the new route is live.
Common questions
How do I know the change caused the improvement?
You need a pre-declared comparison on the same population and period, with no competing change live. If the gain appears only where a promotion also ran, keep the claim open.
What happens when a gate does not clear?
Stop and record why. The dates move, but the work does not continue into the next stage until the missing evidence, owner or rollback path exists.
Can the calendar be compressed or extended?
Yes, because the buyer owns the dates. A stage can finish early when its evidence is complete, and it can pause while a reviewer is unavailable or a safety issue is open.
Which decisions stay outside this sequence?
Legal, tax, accounting and regulatory judgements. Named specialists clear those gates, and the sequence itself gives no legal or financial advice.
