Calculations

This guide explains how to prepare engineering calculations for KBR Infrastructure projects.

Before you begin

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.

Caution

Before starting any work, confirm with the Project Manager you have been added to the project WOC and are approved to do the role you have been asked to do!

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 qualified?

Under Queensland legislation, engineers must be RPEQ or supervised by an RPEQ if:

1. The project is located in Queensland, or
2. The engineer is working in Queensland

If you are not RPEQ and either of the above statements are true, you must be directly supervised by an RPEQ. It is your responsibility to ensure you have the correct supervision.

Caution

The person supervising a non-RPEQ engineer cannot also be the verifier! Refer to Verification for more info.

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.

Creating calculations

1) Confirm the Basis of Design

All calculations must have the Basis of Design clearly referenced. This is usually a document that states what design life, design loads, assumptions, informations, etc that is considered in the design.

Note

If you don’t have a basis of design, how does the person verifying your calculation know that your design is fit for purpose?

Typically the BoD is a stand-alone report that is independently verified and confirmed with the client. In this case, the BoD document number should be referenced. For smaller projects, sometimes there isn’t a formal BoD. In this case, make sure to clearly state what you are designing for and whether this has been agreed with the project manager and client.

2) Setup your calculation file

• Templates: Calculations should be done using the standard KBR templates which have coversheets and KBR headers:
  • Excel
  • Word
  • pdf A3
  • pdf A4
• Document number: Calculations should have a unique number, for example, BEJ123-TD-MN-CAL-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 calculations 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.

Be careful!

Do not work off your local hard drive. Projects and people have suffered when laptops have been broken, got stolen, etc.

3) Perform your calculations

Now the fun starts and you can start preparing your calculation.

Provide context and background

Remember that calculations are often referenced and examined years into the future. It probably won’t be you, but someone who is not aware of the history of the project or the thinking when the calculation was written. If they are looking at your calculations, it means that something probably went wrong and they are trying to fix it. Help them where ever you can and give them as much information as possible.

A good calculation sheet needs to read like a good story.

The only purpose of calculations is to help an engineer make a decision. And humans, generally, can only make a decision after they’ve framed the problem in context of a story.

Therefore, your calculation better be written as if it was a story to help you, your future you, or someone else make or understand the decision at hand.

Be kind to future readers

Assume that the person reading you calculations doesn’t have an intimate knowledge of the project and err on the side of providing too much context and background rather than too little.

As a minimum, it is a good idea to provide the following summary at the start of each calculation. If you are doing many calculations on the same project, you can often copy paste this information from calculation to calculation:

Section	Description
1) Introduction	What is the context of this project, and where does this calculation fit in?
2) Scope	What is covered by this calc? What is not covered?
3) Referenced Docs	What are the relevant standards and codes for this calc?
4) Input Data	What data are you relying on?

Write your calculations

Write your calcs neatly to ensure accurate and clear reproductions can be made. If doing hand calcs on pen and paper, ensure that your handwriting is legible and you have scanned the pages at an appropriate resolution 150 dpi+. Ensure you clearly show what your assumptions and inputs are.

Working with models & software

Your calculation should be reproducable without relying on model files, which often be lost or become corrupt. Ensure you have annotated screenshots to clearly identify what your inputs and outputs are.

At the end, explain your conclusions including any engineering judgement calls you made

Compiling you calculation

• Coversheet: All calculations must have a KBR coversheet which identifies the document number, originator, verifier and other important information.
• File type: Caclulations should be compiled into one single .pdf file, with the cover page as the front page.
• Appendicies: Be sure to create appendicies for any input data, related data or correspondance that may be valuable for a future reader.

Verification

It is the engineer’s responsibility to ensure that their calculations are verified.

Verify everything

Everything that goes out the door must be verified. Document Control won’t let unverified deliverables go out.

Anything that gets used as a part of a final design must be verified by an independent engineer that is approved to do so on the WOC. If you are not sure who can verify your calculation, talk to your Project Manager or one of your Chief Technical Engineers.

Note that the verifier doesn’t automatically ‘win’ if there are any disagreements in the calculation. It is up to both the verifier and originator to agree on the design. This can be difficult sometimes, as usually the verifier is more senior to the originator. Just remember that the verifier sometimes doesn’t have the full background or context behind some decisions and may not be across all aspects of the design.

For more information on the verification process refer to Verification.

Issuing calculations

We don’t generally issue calculations externally, so the ‘Approval’ signature on calculation coversheets can be left blank. The Project Manager or Discipline lead is responsible for the ‘Approval’ signature if the calculation needs to be issued externally.

Templates

Excel calculation file

Word calculation file

PDF A3 calculation file

PDF A4 calculation file

Related procedures

For additional guidance, refer to the following documents:

Infrastructure Design Desk Manual Overarching procedure of the minimum technical requirements on Infrastructure Solutions Australia projects

Engineering Management Desk Manual Overarching procedure of the minimum technical requirements on KBR projects across the globe

Design Document Requirements Procedure for preparing, checking and issuing of documents

Infrastructure Design Document Requirements Procedure for document requirements, approval methods and original documents

Need help?

Contact your Project Manager, Discipline Lead or Chief Technical Engineer.