“If you were a tree, what type would you be?” OK, we’re not attempting to delve into a mindfulness session, but drawing a comparison in terms of ongoing development.
Drop or Retain?
Each year deciduous trees protect themselves by shedding their leaves. The likelihood is the water will freeze and damage their leaves, or winter winds will apply a greater force to the trunk. Shedding them before the winter, allows them to renew with vigour the following year. They may also have become damaged in the summer by bugs or ripped in the autumn by winds, the shed leaves will act as nutrients for the following year. Evergreens, however, protect their leaves with a waxy coating and forms of antifreeze. Their leaves are often smaller, so the tree needs more of them to absorb the sun’s energy.
In the following year after the shut down, deciduous trees still retain their main structure, and the knowledge of how to build new leaves. The evergreens have to be content with the quality of the leaves they have, or have to try and grow new ones while simultaneously shedding the old ones. However, they have been able to continue absorbing energy through their leaves all year round.
Renewing Project Elements
Projects undergoing through lifecycle upgrades often have to decide which route to take. Do you remove the facility, rebuild (possibly including changes) and then deploy, or do you attempt to keep all the existing features in place while swapping out old functionality/parts and replacing them with new ones? Partly this will depend on the ‘down time’ that can be tolerated. A strip and replace is often more efficient, if allowed. The advantage projects have compared to trees, is all the new ‘leaves’ can be prepared in parallel, as long as they fit the trunk it’s a shorter operation to remove and replace the leaves. Whilst the ongoing partial replacement may allow continued operation, there are likely to be cases where parallel components/functions during the swap will have conflicts and interactions that will need to be managed. Of course in either case sometimes fiddling round with the leaves brings no new benefits, if the trunk or limbs are not where they are needed a completely fresh start is needed.
We looked at how Roles can speed up administration of Cradle users.
For an insight into which industry sectors are spending on Requirements Management and Systems Engineering, checkout our mini presentation in this YouTube video
Drawing the November 2021 newsletter to a close, we hope all our customers, suppliers and staff that celebrated Dewali, All Hallows Eve and All Saints day or remembered the defeating of the Gunpowder plot had a happy and safe celebration. 3SL remembered those who fought and fallen on Remembrance day.
Cradle-7.6.1 is the first patch release for Cradle-7.6, it is completely compatible with your 7.6 security code. Users with 7.6 do not need a new security code and can download and install without charge. Users on older versions of Cradle such as 7.5.3 or earlier can move to this version as long as they have maintenance. Simply request a new security code from the 3SL support team and get started!
Bug fixes included in the release are:
Issue found when copying items with change history turned on.
We’ve seen investment from a wide range of market sectors, all of whom have very differing products. However, there are many similarities in the processes that they use, based on their need to manage the same types of complexity.
Project Needs and Goals
Every project seeks to satisfy a set of requirements in a way that maximises compliance and minimises time, effort and cost. All projects must demonstrate that they have met the requirements by passing a variety of acceptance or validation checks. Therefore, RM (requirements management) is not unique to any individual industry.
Depending how you classify your ‘system’, the concepts and activities of Systems Engineering are also not ‘industry specific’. SE (systems engineering) may sound a little grandiose for some projects, but that depends where you draw your system boundaries. You could be modelling sensor data and control signals coming in, describing how these are manipulated and what outputs are expected. Alternatively you could be describing goods inward, shelving process and booking out.
What constitutes a ‘system’ depends on your industry sector, but the need for careful engineering of systems is common to all sectors.
Sector Investment 2020/21
Discover which industries are investing
Using 3SL’s end of year results grouped by sector we have highlighted an interesting change in RM and SE investment over the last year. Whereas aerospace, and military and defence projects had dominated in the past, construction and energy industries have made a heavier investment this year.
Is Requirements Management and Systems Engineering Right for Your Industry?
If you make, design, or maintain a product, process or a development area, the answer is likely yes. Projects are most successful when; they can capture the needs of the stakeholders; help plan and develop the solution; provide traceability and reporting at the end. Rather than asking whether you need a RM and/or SE tool, ask why you wouldn’t want to keep control of your project operations.
Ignore Systems Engineering principles and do nothing
Document using spreadsheets, word processor documents, paper files, cloud drives.
Invest in an integrated tool
This first choice is hardly an option at all. How do you explain to your customers and stakeholders that you don’t really know what needs doing? You don’t know what the risks or boundaries are? You don’t know what you think you need to do to get to your undocumented goal?
Electronic or paper documents are a great start. They can support a basic set of activities, the skeleton of a process. At the very least you have notes as to what, how and where your project is going. The major problems are:
Recording changes and defining the consequential effects of change
Recording dependencies between documents and using these dependencies to ensure that consistency, once it has been achieved, is maintained as the information in all documents changes
Your workload increases enormously as your documentation grows and you must keep each individual element under configuration control and then providing links between each of those documents. How long do you need to spend in that document reference register keeping each need linked to the appropriate design spreadsheet entry……
It is no surprise that we would suggest that an integrated tool as the most appropriate and efficient way to work; to link all parts of your design lifecycle together; provide the means to capture, store and process those requirements; optionally link in system engineering designs; provide full traceability to the output. (Report, document, views etc).
When selecting a tool it is important that it is a good fit for your process. It must meet the needs of your process without being so complex to use that it becomes self-defeating by transferring large amounts of work to manually maintain your documentation set into large amounts of work to manage the complexity of your software tools. This is the main reason why multiple tools can be a substantial drain on your resources, even assuming that you can actually interface the tools to each other.
Cradle can support some or all of your process… it is your choice. You decide which part or parts of your process could be helped by Cradle’s automation, its ability to link and cross reference information, and its ability to automatically track changes. The schema that you build in Cradle reflects how much of your process is Cradle to support, such as to manage and link:
needs -> user requirements
user requirements -> acceptance criteria
user requirements -> system requirements
system requirements -> validations
system requirements -> SBS
system requirements -> functions / behaviour
SBS -> architecture
architecture -> functions / behaviour
architecture -> verifications
functions / behaviour -> test cases
test cases -> test results
These process elements exist in the creation of aerospace / defence platforms, traditionally the main user of these sort of tools and methods. The design of process control systems, and the specification of I&C (instrumentation and control) systems in power plants has many parallels, and this is where we have noticed growth. However, we are pleased to say looking at the detailed data it can be seen that the processes are being applied in a wide range of other situations in so many sectors. The discipline of systems engineering is being applied to great effect to help to manage all their issues in so many industries. We build Cradle to try to automate and simplify the application of these systems engineering techniques, no matter what industry you are working in. Cradle provides our customers with the functionality giving them RM and SE power at their fingertips.
Still not sure whether you could benefit from an RM / SE tool? We’d be more than happy to discuss your projects and processes and make a recommendation. Book a webinar now.
As we’ve pointed out before, October was originally the eighth month, until King Numa Pompilius, inserted January and February. Until then ‘Winter’ was seen as monthless, with only 304 days belonging to named months. A bit of a design flaw. However, as with many systems, it was too onerous to start again, so the sticking plaster situation left us with October, November and December shifted two months from their name origins.
Eight In Life
In physics it is the second ‘magic’ number where either protons or neutrons, are arranged into a complete shell within the atomic nucleus.
Electronics and computing eight is the number of bit in a byte. 8 bits representing -128 to 127 or 0 to 255. If the last three bits of a number (when represented in binary) are 0s then the number itself will be divisible by eight.
In maths, other than 1, it is the only perfect cube in the Fibonacci sequence.
Your wisdom tooth is the eighth tooth in each quadrant of your mouth.
Eight is seen as a lucky number in Asian countries.
It the number of notes in an octave, a note of a frequency and its double.
There are 8 vertices to a cuboid.
Eight is Agile
Consider the two loops of the figure of 8 as the design and implement areas. As you trace round the outside, you start designing and planning and then you sprint round to implement a phase, before returning once again to consider achievements and plan the next step. This Scrum style operation breaks the problem down into small manageable chunks with an ongoing evaluation and planning. If you’re planning or adjusting a process in a Kanban style this repeated return allows changes to be measured and new bottle necks to be identified and alleviated.
An agile approach is an alternative to the traditional waterfall model to design and implement. It has its strengths in development of new or innovative solutions, especially where a degree of trial and prove/reject is also required. However, it should not be seen as a hackers remit. It only works if you clearly break down the problem, set goals and measure achievements. It could be viewed as a series of small waterfall operations defining each iteration.
Don’t Get Caught In A Loop
If your project is analogous to walking round and round a circle, something is going wrong. Walking in a figure of 8 gives you the opportunity to look forward and backwards as you trace your steps. your aim is for a steadily increasing climb.
Last chance to get booked onto the last public training course Document Publisher this year. Document Publisher Course 22nd – 25th November 2021
Following feedback this two day course has been spread over 4 * ½-day sessions to give candidates more time to practice what they have learned, and ask follow up questions at the next session. We’re busy putting together the 2022 schedule and would like to hear from you if there are any topics you would like to see covered, contact firstname.lastname@example.org
When you loop round your design and implement cycle, testing is an important step to validate your efforts.
Cradle’s Test, Execution and Recording module allows a controlled, rigorous way to record, and link your tests, design and requirements. Watch here. For more information read our blog.
We noted that in very hazardous environments robots are needed to repair other robots in this tweet by Kuka UK.
Whether it’s a representation of the CEO to the shop floor worker, or aircraft to the specification of the wing rivet, we all recognise a hierarchy. In Cradle, a Hierarchy Diagram (HID) is a graphical visualisation of how minor elements are combined in increasing complexity into increasingly large collections, to produce the item at the top, the subject of the HID.
Many use the metaphor that it is like a tree, the trunk as the core product, branching off to the smaller and less significant leaf nodes.
The leaves are seen as the lowest level of importance. After all, a tree can survive without a few leaves, and not have any detrimental effect. This is likely true if we were building a house, if a supplier is unable to supply the kitchen cupboards, the house will not ‘fail’. It will remain standing and still be considered a house. It just can’t be considered 100% complete. And it may be a little inconvenient to store your pots and pans.
However, if we consider that the way we normally draw a hierarchy diagram is more like a tree’s core with the roots flowing down. Now, let’s consider what would happen if one small root picked up a detrimental chemical from the soil. This would travel throughout the tree damaging the core trunk. In the case of the aircraft rivet, a change in quality or specification of this lowest level element could have disastrous consequences for the whole aircraft system. Here the nodes (at least some) are crucial to the integrity of the product.
There is no right way or wrong way to represent and think of a hierarchy. It will depend on your organisation / system / product. It may even apply differently to different parts of the system. However, it is important that you consider what your hierarchy represents and what part the end nodes play.
Due to popular demand an extra Document Publisher course has been scheduled this year. Document Publisher Course 22nd – 25th November 2021
Following feedback this two day course has been spread over 4 ½-day sessions to give candidates more time to practice what they have learned, and ask follow up questions at the next session. We’re busy putting together the 2022 schedule and would like to hear from you if there are any topics you would like to see covered, contact email@example.com
Cradle allows you to draw a hierarchy diagram from any linked item. This gives you an instant visualisation of how related components fit together. Watch this clip https://youtu.be/IA4AFZyRrQo and other tips on our YouTube channel, and don’t forget to Subscribe. Find out more in this blog article.
We looked at the benefits of using Thales using robots in the growing, but hazardous offshore wind environment.
We reminded you that, as we move back to offices and workplaces after home working, our environment risks consideration are as important as our product assessments.
Document Publisher November 22nd – 25th November 2021
Due to popular demand, we’ve added another chance to make your output shine with Cradle report creation training – Document Publisher November 2021 course.
“Once you have managed your requirements and development, producing a comprehensive report, automatically based directly on the project data, provides an essential deliverable”
Businesses that have Cradle for their Requirements Management or Systems Engineering process can benefit from additional Cradle tools.
Document Publisher is a Windows® based publishing tool that allows professional documentation to be produced directly from the data within your project’s database. Fully understanding how to configure templates and data manipulation will offer the best output for you to provide to your stakeholders and customers, regulators and other interested parties.
Public Document Publisher Course November 2021
Often the document production task is run by an individual or a very small team. Therefore, this public online course will offer a cost effective way of providing training. You’ll benefit from all the normal learning, but will have the chance to network and share with other virtual attendees from other industries. However, if you have a larger team courses can be tailored and held at your premises / virtually depending on restrictions and requirements at a date and time to suit see here. This will be conducted over four ½ days.
It’s been another strange Summer break this year. We hope you have managed to take a few days to recharge your batteries whether a Vacation, Staycation, Backyardcation. The last 18 months or so have shown what is possible with remote working. We trust with WebAccess, VPN connections, Remote Desktop Access, or SaaS you have been able to continue with your projects in Cradle.
There has been a lot of debate over the advantages and disadvantages of working from home. On one hand you can “just finish” something without needing to leave for a bus or train, on the other hand some of the social interaction and coffee table discussions are missing over video conference. With your computer sat on a desk at home there may be more of a temptation or expectation to sign on ‘outside hours’ to answer emails.
So whilst we are pleased you are reading this August 2021 newsletter, it is important to remember whatever type of break you take, (a change is as good as a rest) it is important to have time away and to refocus on your return. 3SL is happy to advise on flexible configurations of your installation to keep you up to speed wherever and however you continue to work
Keeping your requirements SMART (Specific, Measurable, Attainable, Realisable, Traceable) can easily become nubilous, insufficiently Specific. This can often be resolved by splitting the requirement statement from “The product will do this and that” into two clear statements “The product shall do this” and “The product shall do that”. Cradle’s split feature allows blocks of information to be split into multiple items, each cross referenced to their common source. These new elements are then Specific, and the linking allows them to be fully Traceable. Watch it https://youtu.be/WennmTREWXQ and other tips on our YouTube channel, and don’t forget to Subscribe
“This porridge is too hot, this porridge is too cold, this porridge is just right”
Goldilocks knew exactly what she wanted. Even if she’d not shared her requirements with the bears beforehand. However the measures made were fairly subjective.
In other situations it is much more important to get the mix right. Try building a sand castle with sand that is too wet, or too dry and the product fails, and that’s not just an opinion. If that was part of a concrete mix for a new building, you’d want to be sure it was “just right”.
What Is Quality?
What constitutes ‘quality’ will vary by product and stakeholder. Some may consider a luxury leather bound volume a ‘quality’ product. It would be wasteful and excessive to use such an expensive resource to write shopping lists. It would be more appropriate to use it to record pledges of office for city officials that will be kept in a permanent archive.
Quality may be best judged by the longevity of writing preserved in the volume’s pages. It will be of little use if its writings fade to invisibility in a few years. Copies of the Magna Carta written on parchment have lasted for over 800 years. This would be unlikely had it been written on cellulose based paper with a disposable ball point pen.
How Do You Measure It?
As part of our validation activity, we will need a way to measure the characteristics that we have decided will be used to describe quality. In our example, we could subject our ledger to an accelerated weathering simulation with cycles of varying intensities of UV light, humidity and temperature. We could then check the integrity of the volume’s bindings, its pages and the contrast of the ink and the page.
With defined quality metrics and measurable values for each metric, the quality of each product can be judged against the metrics and accepted or rejected.
What If I Can’t Measure It?
There are some things that are much more difficult to quantify. However that should not stop us trying. A customer requirement to have a soft-touch finish on their product could be met by covering it in foam padding, or a velvet cover. These might be acceptable for a chair, but not much use on the handle of a cold chisel. For this quality metric, the customer wanted something to absorb vibrations and so make the tool more comfortable to use. There may be measures of ‘softness’ in terms of compressibility and stiffness, but these may be difficult to use as quantities; You could argue velvet feels ‘softer’ than a rubberised plastic handle, but the latter will compress more than the former.
In some cases to make the requirement SMART (Specific, Measurable, Attainable, Realisable, Traceable) the specific and measurable aspects may be done by comparison, or actually specifying part of the ‘solution’ in the requirement. Whist well written requirements should not mandate the solution. They should be a detailed expression of the needs, allowing the design and production to choose the most appropriate solution. However, this is not always possible. “The chair must be covered in velvet“, is really a constraint, it is unambiguous and would allow the end product to be undeniably validated. However, we could still debate the “plushness” and whether it is made from artificial or natural fibre.
In the case of the chisel, the main product finish may be specified by meeting a design constraint; such as British Standard BS 3066. This will ensure hardness of the cutting edge impact resistance will be suitable. However, the optional handle would not be covered.
We could write, “The handle should be soft to the touch providing good grip and absorbing at least 50% of the impact force when compared to an uncovered chisel. Properties comparable to the material used on the Club hammer CLBHM002 in the same range should be considered.” This time the requirement is not mandating the same material, it is allowing practical consideration as to what is possible in the manufacturing environment. It does invoke a measurable aspect whist not needing to meet specific values. It also highlights the reasons for the specification, to provide grip. If this came to a point of discussion and the supplier covered the handle in PTFE encased foam, it may be soft but would not be considered an aid to grip. However, a rubber, or texturized plastic would both pass muster.
Strive Towards Acceptance
The book on requirements management might tell you about being precise. Even in the trivial examples given we could all spot flaws. How long does the handle need to last? Does the product have to be water repellent? It would be terrible using a chisel with a lovely shock absorbing handle, if it became cold and soggy at the first sign of rain, or when rinsing it clean.
As either a customer or supplier we can mitigate against these problems, by taking a more agile approach to the whole design. Before final design and definitely before production, a round of review of design and validation criteria should be undertaken. Samples of the handle material can be shared with the customer. The baselined requirement can be updated with a new version, to explicitly state “The handle shall be manufactured from a suitably damage tolerant material, providing a good non-slip grip such as EVA – an ethylene polymer“. We have then full traceability that the requirement was updated as a result of design review. We also have a constraint that can be validated.
A Word of Caution
Whilst communicating with potential suppliers, you also need to ensure a building of trust. Ensure each side has all the correct confidentiality agreements signed. Make sure it is clear who owns the IP on any design. Whilst researching this article, the need to keep your discussions under wraps was highlighted, by Footprint Tools. If details are handed out too freely, you may find a supplier you end up not using plus a competitor buyer, beats you to market. Unfortunately you may also find if your chosen supplier is less than trustworthy they could use your design to create product for another buyer. Quality in this case applies to the contract and the trust of everyone in the engineering lifecycle chain.
At some point or other in business we are either looking to buy or looking to sell a product or service. It’s not a simple interaction, if we are seeking we need to be able to find the product we are looking for. This could be achieved by using a trade journal or directory, or by using your favourite search engine.
However, this relies on the product having been categorised in the way we are seeking. Take, for example, the requirement to add a visitor’s overflow car park at the office. Do you look under ‘builders‘ or ‘landscape contractor‘? On the other hand, as a purveyor of graduated measuring tubes do we advertise under ‘medical supplies‘ or ‘laboratory equipment‘? In truth if costs allow, placing an advert in both categories or key search words is the best option. It would likely be wasted effort placing an advert in the “injection moulding” section, even if that is actually how the product is manufactured.
The seek or sell ethos need not be restricted to buy or sell advertising. It can be applied to usage of your product or service. Under which UI (User interface) heading will the user look to find the ‘preferences‘ setting? Should be able to trigger a report from a ‘reports‘ menu, or from within each ‘dashboard‘? If you provide automotive repairs, should your website show ‘puncture repairs‘ under the ‘Wheels and Tyres’ menu or under ‘Repairs and Servicing‘?
When a user wants to switch on the set-top box, where do they instinctively look for the on/off switch on the remote? (Think, how often is the ⏻ at the top of the control, you’re unlikely to find it in the middle. To illustrate a point, if you see a strange box before the graphic icon, that’s because the rendering of the unicode character ⏻ is not supported in your browser – we thought of that and placed the graphic there too.) Design should be mindful of what and how others look, and what we provide; are we the seeker or the seller.
Survey, Testing/Monitoring, Feedback
Asking potential users, observing usage of ‘sample customers’ and allowing a route for suggestions are all ways we can tweak the efforts we place in the ‘Sell‘ side of the process to help those ‘Seeking‘ the product, facility or menu option. Online advertising tools may help identify routes taken to find, or miss a particular landing page. These can’t be applied to printed journals or directories. Observing a user, not familiar with your product, attempt to operate it, may well lead to reconsidering the positioning of controls. Lastly we should all listen to our end users and provide a method by which they can feedback, e.g. https://www.threesl.com/contact/ .
In April we highlighted the new Test Execution and Recording module available in Cradle. The only sure fire way to ensure your product / service meets the agreed characteristics is to validate and verify the result. Validate the solution meets to the requested product aspect and verify that the final output matches the design. Both these steps require a plan of some description. A set of tests that can be applied to the design or product to demonstrate to the satisfaction of the stakeholders that the system is ‘up to scratch’. In the case of verification, this may be repeated on each or a sample of the project’s output. Of course it would be a bit pointless running these tests without recording the results. The Cradle TEST (Test Execution and Recording (TER)) is designed to do just that.
We thought the digital facility from Arup of monitoring, inspection and recording to provide the best through-life support was a good way to support the customer and ensure longevity, and uninterrupted service.
We were reminded that we’d been Tweeting now for 12 years!
If you want to keep up to date with Cradle installation, instructional and feature highlight videos available then they are available on our YouTube channel. See the play lists and hit the “Subscribe” button.
That’s the summertime July 2021 Newsletter, stay safe, enjoy the sunshine and if you want a topic covered in our August 2021 Newsletter, contact us at firstname.lastname@example.org
If this year in 2021 you’re designing flashing wrist bands for the FIFA World Cup in 2022, then it’s unlikely you’ll be worried about your product’s next ‘development stage’ in 2023. Should you be building a house you’d expect greater longevity. You’d hope the architect had designed it to still be standing in 2039, but you would not have expected them to design elements of your house to provide facilities for you to easily add an extension. If you’re designing a router, it’s unlikely that the product will still be in use in 2027, but it is likely that an iteration of your current design will be shipping to your customers. If you are creating a factory, its likely that decisions you make now will affect how flexible your production line is and how able it is to cope with future developments.
Longevity or Variant Flexibility
There is a difference between designing for a product or product line that needs to last into the future and one that needs to provide a base for a number of variants. They are not mutually exclusive but both have an impact on the effort and cost. Without being mindful of the intended product route, it is not possible to plan for this flexibility. Longevity can also be divided into product longevity and design longevity, both of which can affect your product’s end date.
Considering the examples above, if you are creating the flashing wristband and know that you need red, and yellow variants. That’s what the organisers have asked for, a different colour for the opposing teams. It is also possible, but not yet confirmed, that you’ll need green, orange, and blue variants for the semi and finals, but this is only being ‘talked about’. It would be short-sighted ordering your integrated chip-on-board circuit with a ‘built in drive resistor’ to provide the 1.8v needed for the LEDs; only to find the green and blue models can not be made.
It would be much better to add a requirement to allow this flexibility by designing the current regulating resistor as a separate component allowing the 3.2v needed for the other colours. This is a flexible design variant, it is known about and has a high probability of being needed. The impact of this on the design is minimal. The cost saving; allowing many different bands to be produced with the same chip-on-board IC; far outweighs the cost of the extra pick and place operation to add the separate resistor.
It would, however, be very unlikely that producing a variant that could be connected to a sounder to ‘beep’, as well as flash would be produced. Just imagine how annoying the stadium would be filled with beeping noises. The extra cost of designing the chip to have that facility would not produce pay back. That said, if your company produces other novelties; which include a kids toy that needs flashing and beeping; then you may be able to justify using the same chip design across two product ranges.
In house building, the variants are likely to be 2, 3 and 4 bedrooms or left and right hand versions of semi-detached, properties. The commonalities providing cost benefits, when ordering anything from windows to staircases.
Whilst we expect the house to be still standing, and the factory to still be producing; we’d not be overly surprised if the router had stopped working.
The house design is essentially static. It does not change, unless the architect is commissioned to oversee new builds. In that case they may need to be altered to meet changing building regulations.
The concepts of the router should still be good; there should be aspects of our original design in any current products.
The factory product may well alter, if it’s set up to assemble routers that are around 200mm long by 150mm wide; it would be very short-sighted to design all the conveyors and packing systems to only handle that one size. As soon as the new router design of 150mm by 100mm is required, the whole line would need to be changed. So designing for longevity; making as many of the elements of the system configurable or generic as possible; will allow you to accommodate future variants, even if their details are not yet known. Again a balance needs to be struck; designing the conveyors and packing systems that ‘might need’ to handle 3000mm wide packages, would plainly be overkill.
Our house design could be thrown away after the estate is complete. It may not be possible to keep building the same type of house for twenty years. The product, does however need to be designed to last that long. The system requirements must specify materials which will last, no one would seriously want a house built of straw. Just ask the three little pigs… The products we make on the factory line will have their own longevity, this should have been specified at concept. Some elements of the factory may still be the same. It’s the overall design and operation that we needed to last, not necessarily the products being made. If we’d been assembling the wristbands, by now they will hopefully have been recycled, else they clutter in the attic of our house with not a flash left to give.
We should not consider longevity and flexibility separately. Take the router itself; designing the board to allow the flexibility of adding support for a USB device to future variants is good planning. Adding a spare memory socket to allow more caching, to assist with the expected line speed increase with a switch to FTTP is prudent. Designing software and board layouts to cope with an experimental processor and protocols; that only exist in a university study; are likely to be a waste of effort given the expected lifecycle. Designing the software that could still be in use[*] or the basis of the router you will release in 2030, to cope with dates beyond 2038[**] is likely to be worthwhile!
Ensure your design tool allows you to collate, process, link and trace your variants and plan for longevity. Whether this is via an inbuilt mechanism, such as Cradle variants, or by linking longevity requirements as separate items to your main system requirements.