Software update impact assessment

How it works

Every software update to a vehicle or a product raises the same question first: does it touch something that was approved, certified or assured, and if so what must be recorded and who must be told? This checklist proposes the questions for the way the update is delivered, takes your answers, and says whether type approval is affected, which records and actions follow, what is still unknown and how risky the update looks, area by area.

1. Describe the update. Name the product or vehicle type and the update, say whether it is delivered over the air or in a workshop, list the type-approved functions it could touch, and say whether the vehicle type uses RXSWIN identifiers or declared software versions. Over-the-air updates carry extra questions about power, preconditions, user information and rollback; workshop updates carry questions about the tool and the staff instead.
2. Propose the questions, then answer them. The proposed rows are our own wording of the vehicle-level requirements of UN Regulation No 156, grouped into ten areas: type approval, software identification, safety, cybersecurity, emissions and energy, user-facing behaviour, dependencies, preconditions, rollback and failure, and records. One approval question is added for each approved function you list. Answer each row yes, no, unknown or not applicable.
3. Read the three kinds of question. An approval question with the answer yes means the type approval is probably affected. An impact question with the answer yes raises the risk of the update and needs an action. A control question is a safeguard: yes is the wanted answer, and no or unknown is a gap. You can change the kind and the weight of any row, and add rows of your own.
4. Decide whether type approval is affected. If any approval question is answered yes, the approval is affected and the approval authority or its technical service must be told, who then decide whether the modified type still complies or needs a new test report. If none is yes but some are unknown, the verdict is undetermined. Only when every approval question is answered no is the approval not affected on these answers. Whatever the outcome, the assessment and its reasons are recorded for the update.approval affected = any approval row is yes; undetermined = none is yes and at least one is not answered; not affected = every approval row is no
5. Score the risk. Each row has a weight from 1 to 5. A row scores its full weight when the answer is the unwanted one (yes on an approval or impact question, no on a control question), half its weight when it is unknown and nothing when it is the wanted answer. Rows marked not applicable are left out. The score is the points as a share of the total weight, and the same sum is taken for each area.risk score = 100 x sum of points / sum of weights; area score = 100 x area points / area weights; bands: under 20 low, 20 to 39 moderate, 40 to 59 elevated, 60 and over high
6. Collect the records and actions. Each unwanted answer brings the action or record written on its row. The tool adds the notification to the approval authority when the approval is affected, a renewed declaration of software versions when you do not use RXSWIN, and the written assessment for the update. Give each action an owner and tick it when done.

Sources

The methods and default figures rest on these public sources. The wording here is our own; read the source for its full text.

• UN Regulation No 156, Uniform provisions concerning the approval of vehicles with regard to software update and software update management system [2021/388] (opens in a new tab), United Nations Economic Commission for Europe (UNECE), published in the Official Journal of the European Union, in force 22 January 2021; OJ L 82, 9 March 2021. The paragraph numbers on the rows (7.1.1, 7.1.2, 7.1.3, 7.1.4, 7.2.1, 7.2.2 and 8.1) are from the text read in this EU publication. The authentic text is ECE/TRANS/WP.29/2020/80.
• ISO 24089:2023, Road vehicles, Software update engineering (opens in a new tab), International Organization for Standardization, February 2023. Organisation and project level practice for software update engineering; cited by name only.
• UN Regulation No 155, Uniform provisions concerning the approval of vehicles with regard to cyber security and cyber security management system [2021/387] (opens in a new tab), United Nations Economic Commission for Europe (UNECE), published in the Official Journal of the European Union, in force 22 January 2021; OJ L 82, 9 March 2021. The cybersecurity counterpart of Regulation No 156; cited by name for the cybersecurity questions.