Nothing new there, you will say. But as projects become larger, the number of constituent parts increase and the relationships between them become more complex. And it's here where problems can arise; when elements of the design change, can you ensure that the changes are applied to all the relevant parts of the system – and can you prove that?
That certainly applies when the project is housed in one building; but when it is distributed across a number of sites, the need for a system to keep things under control becomes more apparent.
Requirements management has its roots in the automotive and defence sectors, where everything is designed with safety in mind and where companies have to prove they did everything possible to avoid problems.
Christian Christophoridis is vp of product management with Visure Solutions. He said many companies spend a lot time in producing this evidence manually. "They have to comply with many standards and have to react to different customer requirements within weeks. Despite this, you would be surprised how many companies still use Excel, even though there's solutions that would make their life easier."
Modern products use components from various suppliers, must come together quickly and function as required. "To do this successfully," Christophoridis asserted, "product requirements must be managed using an automated system that links each requirement directly to its associated tests and deliverables. Developers can quickly and easily trace to the point of failure, implement corrective measures and validate the product."
Visure has recently released Visure Requirements 4.5, a software system designed to maximise analysis and team efficiency. He claimed version 4.5 features a 'significant set of improvements'.
"One of the things we worked out was that if people don't like software, they don't use it. So we spent a lot of time analysing use cases and performing interviews with customers and internal experts to work out what needed to be included."
According to Visure, Requirements 4.5 has a simplified interface and a process architecture that streamlines requirements capture, analysis and management. The result, it believes, is a faster and more powerful requirements engineering tool for product development.
"It's an ecosystem in which any stakeholder can collaborate on the requirements which define the system being built," he continued. "Because not everyone will be in the same office, you need a single source of truth which can be accessed in different ways. For example, a manager might want to see which items have what priority, while a design engineer might be more interested in the decomposed requirements to see what needs to be done. Any person holding any role can go into the system and see what they are interested in. We have put the emphasis on requirements analysis."
Visure Requirements 4.5 manages all requirements related information in a way that reflects how the data flows and interacts during the product development process. Any requirements related information – such as different levels, test cases and use cases – can be configured, related and analysed based on process needs.
Christophoridis is keen to suggest that software products such as Requirements 4.5 provide a better solution than the use of Word or Excel, for example.
"If you write requirements documents using Word or Excel, you end up copying a lot of common requirements. But what happens if the customer decides on something different? In that case, you have to go back to the core requirements so they can be changed. But history tells us that people often forget to change copies."
So what benefits does Christophoridis attach to a requirement management system? "It brings a new culture and discipline to the process," he claimed. "But people need to work differently; they have to change the way they think when they are developing a system. It's like introducing a quality management system; people have to understand the truth no longer lies in Powerpoint and similar systems – it's available to everyone, depending on their access rights."
He also believes requirement management systems will boost productivity. "You will see benefits in terms of traceability and impact analysis," he claimed. "Traceability allows you to prove coverage on various levels; for example, all customer requirements. And you can also derive test requirements from customer requirements, allowing you to identify gaps in test coverage."
Companies who will need their products to undergo compliance testing can use the templates to define requirements standards and can reuse the template across teams and product lines. In this way, defined processes can be enforced and a common requirements structure imposed across an organisation and its supply chain.
"You can put in the standards which you have to comply with and link to the requirements and test cases that respond to the constraints. It will tell you 'which parts am I not fulfilling?', 'if I fail this test, will I still be compliant?' and 'what features will be impacted by failure?'."
Christophoridis said that, when he was a systems engineer, he had to generate a lot of documentation to prove systems were compliant. "We spent a lot of time preparing information and ticking boxes, but it was a manual process; when a new version of the requirements was issued, we had to go back through it all again.
"Now, with software like Requirements 4.5, you can import changes and the software will tell you what those changes mean. The box ticking is done automatically and the person in front of the screen has a better understanding of the requirements content."
Requirements 4.5 is 'process agnostic', says Visure, and integrates process, quality enforcement and collaboration in one platform with views tailored to particular roles.
"Anything you do that has more than two stakeholders," Christophoridis concluded, "needs requirement management. By putting a requirement management system in place, you avoid ambiguity and can prove things have been done."
Traceability tool
If a project needs to comply with safety assurance measures, such as DO-178/254, then traceability must be readily available throughout all of the project's phases to enable an understandable and efficient validation process.
To help with this, Atego has launched Trace, a software tool which automates requirements traceability and error detection. The tool creates traceability matrices across existing engineering lifecycle documents; including requirements engineering tools, such as DOORS, and general purpose documents such as Word, PDF and Excel.
"Atego Trace is useful for customers who build safety certified systems and software," said Hedley Apperly, vp of product and marketing. "Atego Trace was designed by our US Federal Aviation Authority Designated Engineering Representatives and has been proven extensively on multiple DO 178/254 and other compliance projects."
Atego Trace captures custom tags embedded in existing documents to provide top to bottom and bottom to top traceability matrices. These results can be used to analyse the traceability between system requirements, designs, code and tests. They can also show traceability improvements over time and act as compliance evidence.
