Verification
This guide explains how to verify engineering calculations for KBR Infrastructure projects.
Checking a calculation done by another engineer can be one of the most important responsibilities of your engineering career. After you give your approval of the calculation, very few people will question its accuracy because it was done by an engineer and ‘it’s been checked!’. An error will be that much harder to find and lives could depend on it. Your checking of the calculation could well be the last major safety hurdle the work will have to pass.
Before you begin
Section titled “Before you begin”Are you on the WOC?
Section titled “Are you on the WOC?”All engineering calculations and verifications must be prepared in accordance with the project-specific Work Operation Classification (WOC) Matrix. This document defines who can originate, verify and approve calculations.
Before any document gets issued, document control will check who has done the work and whether their name is on the WOC. Save yourself the last minute panic trying to get deliverables out the door and make sure you’re on the project WOC to start with!
Are you independent?
Section titled “Are you independent?”Only someone that is independent to the design may sign off as verifier. This is to ensure technical integrity through the design process.
Some of the time, it’s not black and white whether a person is independent or not. If you’re unsure, consider if something goes wrong — would a jury or judge consider your review to be independent?
Do you have a budget?
Section titled “Do you have a budget?”You need to understand the budget/hours that have been allocated for this activity. Not getting clarity or agreement on the hours to do the work causes unexpected costs to the project. If you don’t agree that the work can be done within the proposed budget, that’s okay too. Discuss with the project manager to agree a way forward before doing any work.
Verifying calculations
Section titled “Verifying calculations”1) Setup your verification file
Section titled “1) Setup your verification file”- Templates: Verifications should be done using the standard KBR templates which have KBR headers. Note that the originator should supply the calculation coversheet already completed.
- Verification Record: Verifications must use the Verification Record Form to summarise the outcome of the verification.
- Document number: Verifications should have a unique number, for example,
BEJ123-TD-MN-VER-0001. It is the responsibility of the engineer to designate this number and ensure it is unique. To avoid duplicating numbers, the Project Manager should setup a document register to identify documents. - Storage: All verifications need to be stored on a shared workspace that is backed-up. This varies project by project and includes Sharepoint, Documentum, ProjectWise or the Network Drive. If you are not sure where to store your calculations, ask your Project Manager.
2) Review the calculation purpose
Section titled “2) Review the calculation purpose”Identify what the calculation is determining. The originator should include a clear statement of purpose. If missing, consider rejecting the calculation—without a defined purpose, results may be misused.
3) Check the Basis of Design
Section titled “3) Check the Basis of Design”Verify the calculation references the Basis of Design document, which defines design life, loads, assumptions and other parameters.
4) Evaluate the assumptions
Section titled “4) Evaluate the assumptions”Assess whether assumptions are appropriate and produce sufficiently accurate results. Watch for:
- Assumptions that oversimplify (neglecting mass, assuming inviscid fluids, frictionless contact)
- Complex calculations where assumption impacts are unclear
- Trade-offs between calculation simplicity and accuracy
5) Consider the references
Section titled “5) Consider the references”Check that references are appropriate and current. Avoid bias toward either recent publications or “classic” sources—focus on whether the reference suits the application.
6) Confirm the inputs
Section titled “6) Confirm the inputs”Verify the calculation analyses the correct component with the correct geometry and materials. Check:
- The design is for the correct element/part
- The geometry or materials match what is being shown
- Loads have been correctly considered
7) Replicate the results
Section titled “7) Replicate the results”Use one or both approaches:
- Direct replication: Step through the calculation methodically. Use this for most hand calculations.
- Indirect replication: Calculate the same result using an alternate method (different software, numerical vs analytical approaches, alternative calculation methods). Similar results from different methods increase confidence.
8) Review failure modes
Section titled “8) Review failure modes”Confirm all credible failure modes have been considered. Common oversights include:
- Calculating only yield/ultimate stress without fatigue life or serviceability
- Missing progressive failures (such as thread stripping in dissimilar materials)
- Overlooking secondary load paths
9) Assess result reasonableness
Section titled “9) Assess result reasonableness”Check whether results align with engineering judgment and experience. An unreasonable answer suggests a subtle error may exist, even if each step appears correct.
If a result seems unreasonable but proves correct, understand why. Identify which parameter combinations produced the unexpected outcome.
10) Confirm documentation
Section titled “10) Confirm documentation”Confirm that the calculation is correctly formatted and laid out with the correct document numbers and revisions.
11) Close out your verification
Section titled “11) Close out your verification”Document your findings using ATT-GL-KBR-INF-0549d Design Documentation Verification Record. Record comments and corrective actions taken. Attach PDF copies of markups or screenshots.
Work collaboratively with the originator to resolve disagreements. The verifier doesn’t automatically prevail—both parties must agree on the final design. Remember the verifier may lack full context on certain design decisions.
Common verification pitfalls
Section titled “Common verification pitfalls”Avoid these frequent causes of missed errors:
- Using the same spreadsheet or software as the originator
- Confirming numbers without checking underlying logic
- Relying on the same reference data as the originator
- Skipping load path verification (calculations may be arithmetically correct but apply forces to wrong elements)
- Following the same calculation sequence, repeating the same errors
- Rushing verification under time pressure
- Expectation bias (assuming the answer should match what you expect)
- Not checking edge cases and boundary conditions
Templates
Section titled “Templates”Related procedures
Section titled “Related procedures”For additional guidance, refer to the following documents:
Need help?
Section titled “Need help?”Contact your Project Manager, Discipline Lead or Chief Technical Engineer for assistance with verification questions.