H&T

An architects view of PaaS

Cloud computing has meant that organisations have ability to scale and deploy solutions without much consideration of the underlying hardware. The next evolution of cloud is PaaS - delivering software development; lifecycle management and runtime execution environments.

While cloud and new application development technologies excite geeks, the real benefits for the business are: 

• Faster time to value - build applications quicker
• More reliable applications - as apps are built with clicks not code
• Improved agility - changes to underlying business processes can be implemented quicker

PaaS providers have either evolved from Infrastructure; SaaS; or Middleware players. Adopting a PaaS provider for your business raises some fundamental architectural questions. Openness is typically the key concern. 

Open or proprietary

By selecting a PaaS provider that has closed stack you expose yourself to vendor lock-in and in perpetuity subscription models. . If you select a proprietary provider such as Force.com, you are locked into the platform and have no alternatives for deployment i.e. the code, workflows and user interfaces that you have developed are specific to your PaaS provider.  Of course the benefits of the closed system may outweigh these concerns.

Cloud vs On-Premise

A critical question is where do your applications need to run? Options are either on-premise within your own infrastructure or externally hosted in cloud environment (public or private). If you need to run them internally, this significantly reduces the vendor landscape and increases complexity and associated governance and management (called "devops"). Some providers such as Outystems allow you to generate code in 'traditional' software stacks such as .NET or J2EE. 

Your core ERP system

Your main corporate back-end system can influence your PaaS selection. Clearly your PaaS selection should "play nice" with your ERP. Certain vendors such as Mendix provide integration into core ERP backends and may be a solution to expose your ERP as your system of record. Of course choosing the right cloud integration solution for your chosen platform will make integration between the various systems easier.

Application Development Strategy

Another key factor would be your development team composition and your business model for application development. Offshoring or outsourcing development skills has been a common approach to reduce application costs. Do you have a specific application development language capability or strategy internally and want to select a PaaS platform aligned with these skills? E.g. .Net or Java

Security and Legislative requirEments

Ensuring your PaaS provider supports your Identity, Authorisation and Access solution is important so that applications can be provisioned in a co-ordinated fashion. Certain legislation may preclude your organisation from storing data in 3rd party solutions, forcing you to consider offerings that allow private deployment options.

Business Users vs Developers

Who will be creating applications? PaaS platforms allow quasi-technical individuals to deploy and test applications with very little training. It may be that you see the benefits of using Model Driven Development (MDD) techniques to reduce errors of your developers. Certain PaaS platforms such as Outsystems automatically generate code in .NET or JAVA.

Conclusion

Selecting a Paas for your company should be not be taken lightly, the key factors vary between organisations and System Integrators. We at H&T have developed a number of solutions using 3rd party PaaS providers and recommend the following: 

1. Create a short list of vendors based on your specific requirements taking cognizance of points above. Request our PaaS evaluation matrix. 
2. Prototype an application, most vendors offer free trials and development environments.
3. Determine how integration and security between your existing applications in your landscape will be handled.
4. Build a ROI model and understand the "additional costs" that platform introduce such as storage, premium feature sets 
5. Understand your compliance environment and review regulations that apply to your geography / industry. E.g. Data privacy laws, archival requirements