Exceptions to guardrails¶
Guardrails are defaults, and sometimes the right answer is different. The exception process gives you a quick, recorded decision - and tells us when a guardrail needs to change.
Draft - to be confirmed
Parts of this page, such as names, timings and thresholds, are still being confirmed by the architecture team. Use it as a guide, and check with your solution design authority before relying on the detail.
Which process¶
| You cannot meet... | Route | Record |
|---|---|---|
| A Could guardrail | No process needed | Optional |
| A Should guardrail | Your solution design authority | An ADR |
| A Must guardrail | The Technical Design Authority | An exception request and an ADR |
| A security control | The security exception process, alongside the above | A security risk record |
Exceptions to the software development standards¶
The Defra software development standards are mandatory, and the Delivery Architecture team handles exceptions to them through its own governance process - see software development in the Defra Digital Service Manual. Some guardrails, such as GR-DEV-01 and GR-HOST-01, cover the same ground.
To be confirmed
TODO: how an exception to a Must guardrail agreed at the Technical Design Authority relates to the Delivery Architecture team's exception process for the software development standards - whether one request can cover both, and which comes first.
What a good exception request includes¶
- The guardrail id and what you propose instead
- Why the guardrail cannot be met - the user, business, technical or commercial reason
- The risks of the exception and how you will manage them
- How long the exception is needed, and what would let you return to the guardrail
- The cost of meeting the guardrail, if that is the reason
Principles¶
- Time-limited. Exceptions have an expiry date, normally no more than 12 months, and are reviewed before renewal.
- Recorded in the open. The exception register is published, except for security-sensitive details.
- Quick. The TDA aims to decide within 10 working days of a complete request. Urgent requests can be handled out of cycle by the chair.
- Feedback loop. Every quarter, the architecture team reviews exceptions. Where several teams need the same one, we propose a guardrail change to the TGB.