Traceability: an alternative to expensive tools?

One of the most important concepts in systems engineering is traceability. This was also used in the 1960s, although the work was document-based. It worked, but was very laborious.

We now have very powerful tools that support us with traceability. But these are expensive. The investment is justified if we are developing complex, safety-critical systems. However, many small projects would also benefit from better traceability. What alternatives are there? That's what this article is about.

The added value of traceability

There are many good reasons to link the artifacts of the system (see Traceability - why actually?), because this gives us great added value:

• Completeness - For example, we can prove that every requirement has been considered in at least some way, or that every component has been tested in at least some way.
• Responding to changes - Traceability enables us to understand the effects of changes and only need to revise the parts of the system that are affected.
• Navigation - Quickly jump to relevant content (thanks Carsten!)

Links can be established in many ways: A Cross-reference in Word is a trace, just like a hyperlink on this website. However, the two added values just described cannot be realized so easily with this type of traceability.

What expensive tools offer

Modern tools such as DOORS, Jama or CodeBeamer (requirements) or Cameo, Enterprise Architect or Rhapsody (system models) not only allow the creation of traces, but also their use to create real added value. For example, almost all modern RE tools have the option,

• mark links as suspect when changes are made so that they can be reworked,
• carry out an impact analysis that tracks the effect of a possible change across several levels,
• to identify gaps in traceability,
• Create tables that represent a mapping (assignment of functions, etc.)
• Support the whole thing with versioning, baselines and branches to manage development cycles cleanly and meet compliance requirements.

These features can only be found in "expensive" tools. Not all manufacturers have a public price list, but all are in a "similar" (factor 3) range, around €1500 per user per year.

Codebeamer is available from €828 per user per year (Price list)

You have to be careful not to compare apples and oranges here: There are huge differences in terms of features, there are node-locked and floating users, etc. The trend is towards subscriptions in the cloud, but many tools can also be purchased for a one-off price for installation on your own servers. Of course, updates then cost extra again...

Anyone developing mobility solutions in accordance with ISO 26262 and ASPICE cannot avoid an expensive tool like the ones just listed. However, traceability is desirable for simple products. Here, the price of such a solution often cannot be justified.

Office - often the entry point to traceability

Office is still the most widely used tool for product development in 2020. Not only Word and Excel, but also PowerPoint can be found on a SharePoint server. And that's fine for small projects. If the specifications do not exceed five pages, then it is still manageable. Problems arise when the complexity increases or when compliance comes into play.

The only sensible way of traceability in Office is Excel. Simplified, one element can be in the left-hand column (e.g. requirements) and the linked element in the column next to it (e.g. test). There are two potential problems here:

• Only 1:1 relationships can be reasonably mapped here (yes, 1:n is also possible, but awkward and bulky)
• No reasonable versioning.

Wikis & ticket systems

Wikis are websites whose content can be easily changed by the user and make intensive use of hyperlinking between the content. There are many free wiki systems, including the one on which Wikipedia is based. In the commercial environment, Confluence from Atlassian is often used. Even though this tends to work from a document perspective, smaller units can still be created quite easily, which simplifies traceability. For example, one wiki page per chapter, so that the specifications are then made up of a dozen wiki pages. Then at least each chapter can be linked, which makes traceability a little more granular. Furthermore, each wiki page is versioned.

Ticket systems are also widely used. There are free systems such as Bugzilla, as well as many web-based systems with commercial models, such as gitHub or Jira. Fine-grained traceability can be used here. However, ticket systems lack many features that professional RE solutions have, for example:

• No document structure - In contrast to RE systems, the tickets can often not be arranged in a tree structure in order to perceive them as a holistic "document".
• No baselines - it is often not possible to version a group of tickets, only individual tickets
• Primitive traceability analysis - things like suspects, gap or impact analysis are either not available at all, or can only be realized clumsily via filters and the like.

There are providers who have recognized this problem. For example, there are plug-ins such as R4Jthat extend Jira with functions for requirements management. This can also be a good solution in some situations. We just shouldn't expect miracles, because at some point you reach limits that cannot be overcome by the underlying ticket system.

Plug-ins based on ticket systems (such as R4J for Jira) can be sufficient in some cases, but limits are quickly reached here too

What else is there?

To say it up front: I am surprised at how few useful traceability solutions I have found. When it comes to traceability in requirements management, it seems to me that ReqView worth mentioning. At €330/user/year, this tool is not exactly cheap, but it is significantly cheaper than traditional RE tools and promises a similar range of functions.

Otherwise, there are still many exotic products that can be "bent" for traceability, such as Mindmaps for example.

Traceability can also take place outside the tools in which work is carried out. There are various solutions for this Cross-tool traceability to realize. Well-known candidates are Tasktop or Zapier.

Even if traceability comes from systems engineering, it is not limited to this. Wherever information elements are linked together, we are dealing with a type of traceability. In this respect, I also looked around here, but found little that was "obviously useful". In project management, for example, traceability has been used for decades with Gantt charts practiced. Even if there are points of contact with systems engineering here, this does not help us with traditional traceability.

Conclusion

Yes, there are alternatives to expensive tools for practicing traceability. But not many. I would be very interested in the opinion of my readers and would be delighted if you would take part in the survey in the right-hand column.

Image: Pexels / Pixabay