To build a business case it is key to understand the existing architecture and where your applications are hosted.

When it comes to SD-WAN the conversation here should begin with “where” are your applications hosted and how are they used. It is not where most organisations start but there is good reason for doing so.

If your applications are primarily hosted in a centralised data centre then traditional dedicated networks based on MPLS will offer the best connectivity to the application from the end user. However, if your organisation, as many others are now doing, is moving increasingly towards cloud hosted application (SaaS/IaaS/PaaS) and NaaS solutions, then a different approach is needed, and SD-WAN is the better choice. Read more in my MPLS Vs SD-WAN blog.

So ask yourself ‘Where is your business heading’, e.g. if there is a general view that you want to adopt a cloud centric approach to application hosting, then this should influence how you are architecting your network and therefore what technology would be right to consider e.g. SD-WAN.


The business drivers for SD-WAN have remained largely the same for the past few years primarily as a result of the increased focus around digital transformation. Typically they are: Collaboration and flexible working, improved application performance, insight and control, cloud adoption or cloudification, simplifying and expediting the onboarding of new acquisitions and the removal of legacy infrastructure, the complexity that is associated along with that and the mitigation of inflexible MPLS contracts.


This is where most companies will have started and for good reason, digital transformation has a lot to do with the increased adoption of SD-WAN….

So having identified the benefits you want to achieve is most likely the reason you will have ended up considering SD-WAN in the first place. Improving application performance can deliver improvements in user experience which can improve business performance, increase revenues, reduce churn… all well documented boardroom benefits. Cloud adoption (planned or forced) together with integrated security and application insight which provides intelligence and governance are other benefits that lead organisations to SD-WAN, and that is where most start their journey.


Organisations have a number of options when it comes to deciding how to adopt SD-WAN, ‘Do-it-Yourself’ (DIY), Co-Managed or Fully Managed.

SD-WAN is now fairly established as an enterprise networking solution, I would be interested to know how many organisations who have adopted (or who have started to adopt) SD-WAN would, in hindsight do things differently. As I have said in my blog ‘DIY SD-WAN’ , there is a perception that SD-WAN is straight forward to deploy and manage the reality however; if you are to realise its full value, can be quite different.

Once you have agreed the criteria for a business case, the vendor technology is only half of the conversation, and in effect provides the tools to build your new network. It is the role of an integrator to take these tools and ensure that the solution delivers against the business case criteria. The challenge here is that organisations often don’t have the necessary resource to manage the full lifecycle of the project. There are many myths surrounding the selection, deployment and management of SD-WAN which can leave organisations with project tension, technical fatigue and valuable resource tied up for prolonged periods of time with delivery deadlines missed and investments squandered.

So it is important to build in to your business plan consideration for the adoption models available e.g DIY, Co-Managed etc, and costs thereof for the full lifecycle of the project.

The other key element for the business case is understanding the current network security architecture and the associated changes that will be required in this area to support features such as local internet breakout that are common with SD-WAN deployments.  Undertaking a network evolution to move to SD-WAN, also tends to bring increasing demands on the network security architecture and often in turn drives a subsequent security evolution to move towards cloud scale security services such as CASB, FWaaS and Secure Gateway.  Gartner calls this Secure Access Services Edge (SASE) and these two areas need to be considered in any business case, as whichever way you approach these architectural evolutions, from a network first perspective or a security first perspective, they drive the adoption of the other, and so this needs to be factored in when looking at associated projects and importantly budgets.



The ‘Pre’ business case

Understanding what problems you are trying to solve – what are the challenges with the existing business solution and understanding the reasons for change are important, because the biggest risk to the business case is not being able to articulate the value of SD-WAN Vs renewing a contract for MPLS services.

Understanding the impact of associated services such as Security and whether the evolution of the network will trigger by necessity an evolution of the security architecture.

Increasingly we are finding organisations are having to demonstrate that the business case reflects not only the tactical requirements of the network refresh, but also and perhaps more importantly how it supports and underpins the organisations strategic ambitions.  Many of these are based around Environmental, Social or economic responsibility and you need to be able to articulate how the project will move the business nearer to some or all of these key objectives in order to get executive sign off.

Post Business case

So, now you have sign off from the executive to explore the market and investigate/tender for a suitable solution. This is where you try to translate the business objectives and strategic goals into technical commercial and service requirements and take this to the market.   Investigating the SD-WAN market can be quite daunting and as discussed in my previous Blog SD-WHO, there are currently more than 40 technology vendors who all claim to have an SD-WAN offering, often with differing levels of feature support.  It is important to continually review the available feature sets against the business objectives from the initial case as feature road map evolution in this space is fast paced and there may be more than one route to satisfying all the key business requirements.

As mentioned previously, network evolution can subsequently drive a need for security evolution so factoring in alliances, pre-integrations and partnerships across the SD-WAN vendors and the Cloud Security vendors is also important for the longer term viability of the solution.

The last area of focus for the market exploration relates to how your organisation wants to procure the technology and services.  What I mean here is do you want to buy both the SD-WAN and underlay connectivity from the same provider, or just the SD-WAN.  Both have benefits in different use cases and this is down to the appetite of the business to move from a ‘single throat to choke’ model to a ‘best in breed’ approach.  Then there is whether the intent (albeit maybe not the resource or skills) to go self-managed, or the acceptance that specialist assistance is required and move more to a co-managed or fully managed solution.

Ultimately these areas will all build into the specific requirements that your business has of the SD-WAN solution, and then there is the realisation that the vendors can provide the technology, however the ability to take the technology and deliver against the objectives that were promised in the business case needs a specialist integrator such as Axians.

In the next Blog SD-WHEN we talk more about where in the process it makes sense to engage a specialist integrator like Axians, and how there is no such thing as “too far down the line” to bring an SD-WAN project back on course.

Chris Gilmour CTO and SD-WAN lead for Axians