In large projects, a single contractual document often known as the Contract End Item (CEI) governs the final product design. Each requirement of the contract is individually numbered to allow for performance verification of the end item. Because the projects are usually complex, this set of requirements is broken down and allocated to different subsystems.
These subsystems also have a set of requirements, and each requirement must be traceable to a requirement above it in the document hierarchy. No requirements should be introduced at a lower level, and each requirement in the upper level must be traceable to a document below it. The hierarchical relationship between the requirements is documented in a Traceability Matrix. The technique can be used for many kinds of hierarchical relationships in layered designs.
When I worked in the aerospace industry many years ago, such a matrix was maintained manually. Today, software takes care of this function. Another option, though, is to use Excel. I doubt that Excel's designers thought the auditing features would ever be used as an end in itself, rather than a means to an end. But it's possible because the auditing tool within Excel permits a graphical representation of the precedents and dependents of a particular cell.
Each item of the CEI is listed in one Excel column. (It would be possible to create a VBA program to read the document automatically and include the first line of the requirement together with the numbering, but that's beyond the scope of this idea.) The items of the lower document are listed in another. A third column would show the origin of the derived requirement (see the figure).
For instance, the CEI requirement 1.3.10 (in cell A11) traces to two lower-level requirements in cell C9 and cell C15. Therefore, cells D9 and D15 have the Excel formula =A11. Clicking on cell A11 and then following the sequence Tools | Auditing | Trace Dependents graphically shows which subrequirements depend on the principal requirement. If the principal requirement is modified, it's very easy to see which dependent requirements may need to be updated. The converse also is true. Given a particular lower-level requirement, it's easy to see what principal requirement was the driver using Tools | Auditing | Trace Dependents.
A subrequirement that derives from multiple primary requirements can be achieved using the concatenation of the cells in the reference coupled with a line-feed character. For example, if CEI requirements 1.3.3 and 1.3.4 drive requirement 2.1.9 of the lower document, cell D11 would contain the Excel formula =A4 & CHAR(10 )& A5. To achieve the multiple line effect, the cell should be formatted to allow Wrap Text (in the Alignment tab of the Format Cells dialog).
This worksheet, Traceability Worksheet.xls, can be found in the online version of this article. It includes macros that:
Show the dependents of a selected cell
Show the precedents of a selected cell
Clear all of the dependents and precedents indicators. (Incidentally, saving the file also clears all of the indicators.)
Excel doesn't directly allow VBA to detect cells that have no precedents or dependents. But through the kluge of forcing an error, it's possible to create this functionality. I've also added two macros to search through a column and find the cells either without a precedent or without a dependent. When a cell is identified as missing the relationship, it is colored red. Finally, there's a macro to clear this indicator.
how can you show the word document of the requirement here itself and each requirement say 1.1.1 will hyperlink to its dependent requirement? I am a starter, so I do not know much about this? I have had a look at requisite pro tool also.. please help me out here, also is there are some reading material for building tracebility matrix easily and maintaining it
Anonymous -November 24, 2008
This document has no information about RTM.It is waste.
Anoy -November 17, 2008
Awesome. Thanks.
Anonymous -March 14, 2008
Thanks for your useful tips. It helps!
chow -March 02, 2008
To see a spreadsheet that takes this functionality a little further and generates a Traceability Matrix along, visit www.imvisions.com
Tim -February 13, 2008
good
Anonymous -January 28, 2008
That's really neat and useful. Thanks you!
Ruth -August 02, 2007 (Article Rating: )
Rating Only
Rating Only -July 25, 2007 (Article Rating: )
It is a great way of doing it.. save a lots of time.sime and well executed.
Zaks -December 19, 2006
Please provide the Template for tracibility matrix.and Explain how to use that one?
Regards, sankari
Anonymous -September 18, 2006
This article is absolutely phenomenal ! Thank you, thank you, thank you. You have saved me untold hours of work.
Anonymous -June 02, 2006
Simple, low cost and beautifully executed.
Engineer -April 06, 2006
Incredible! I really appriciate the approach. Although I was using Excel for traceability Matrix for quite some time, but this tip will change my life. I am saved from automation cost. Thanks.
Anonymous -January 16, 2006 (Article Rating: )
The article states that "given a particular lower-level requirement, it's easy to see what principal requirement was the driver using Tools | Auditing | Trace Dependents." Shouldn't that be "Trace Precedents"?
Very interesting acrticle. I'm a Systems Engineer, and am currently in the requirements definition phase of the project. Tracing from document to document is very important in my line of work. Thanks for the tip. I think Excel is awesome. You can do a lot of stuff with such a simple to use program.
...ron...
Ron -February 14, 2005 (Article Rating: )
Clever use of existing tools found on anybody's desktop.
Anonymous -February 09, 2005 (Article Rating: )
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