Which cloud model suits our business?

The most suitable cloud model is the one that matches each workload’s data sensitivity, operational requirements, integration needs and governance controls. For many businesses, the decision is not simply between public and private cloud: different applications may need different hosting arrangements, and a hybrid design can connect them where appropriate.

Public cloud uses infrastructure shared between multiple customers, with each organisation’s systems and data logically separated. The cloud provider operates the underlying facilities, hardware and core platform, while the customer controls its accounts, applications, configurations and data. This model is often suitable for standard business applications, collaboration tools, web services, development environments and workloads that benefit from readily available capacity.

Public cloud can reduce the need to purchase and maintain physical infrastructure, but it does not remove the customer’s responsibilities. User access, data permissions, device security, backup arrangements, configuration and regulatory controls still need to be designed and managed. Costs also need monitoring because consumption-based services can change as storage, users, processing or data transfer increase.

Private cloud provides cloud-style computing resources for one organisation rather than a shared customer base. It may be hosted in the organisation’s own facilities or in a dedicated managed environment. Private cloud is worth considering where workloads require more control over infrastructure design, network separation, data handling, legacy integration or specialised security policies.

The additional control of a private environment usually brings greater responsibility. The organisation or its technology partner must plan capacity, maintain the platform, apply security updates, monitor performance and manage resilience. A private cloud is therefore not automatically the best option for sensitive data; the relevant question is whether its controls, operating processes and assurance arrangements match the business requirement.

Hybrid cloud combines public and private environments, allowing workloads to remain in different locations while connected through controlled networks and identity systems. For example, a business might retain a specialised application in a private environment while using public cloud services for collaboration, analytics or customer-facing systems. Hybrid designs can also support gradual modernisation where existing systems cannot be moved at the same time.

Hybrid cloud is more complex to govern than using one environment. The business needs consistent identity management, access policies, monitoring, backup, security controls and data classification across both sides. It must also understand how applications exchange information, where copies of data are created and what happens if a connection between environments is interrupted.

Assess the workload before choosing the model. A practical assessment should consider:

• Data sensitivity: identify personal, financial, commercially confidential and regulated information, then define who may access it and where it may be stored.
• Compliance and contractual duties: check requirements relating to retention, audit evidence, data location, access logging and supplier assurance.
• Application dependencies: map databases, file shares, authentication systems, integrations and devices that the workload relies on.
• Performance requirements: consider latency, processing capacity, storage speed, availability needs and the effect of network connectivity.
• Operational capability: establish who will manage configurations, security updates, backups, monitoring, user access and incident response.
• Financial control: compare the complete cost of ownership, including subscriptions, migration, connectivity, management, storage, support and future growth.
• Portability: review how data can be exported and how applications could be moved if the business changes provider or architecture.

Do not confuse the deployment model with the service model. Public, private and hybrid describe where and how infrastructure is organised. Infrastructure as a service gives the customer more responsibility for operating systems and applications; platform as a service shifts more platform management to the provider; software as a service delivers a complete application. A business may use all three, with different security and administration responsibilities for each.

A useful selection process starts with an inventory of applications and data rather than with a preferred technology. Classify each workload, record its dependencies, identify its control requirements and then compare suitable hosting options. Test assumptions with a limited migration or pilot where the technical and operational risks are understood. The design should document access controls, backup and recovery, monitoring, supplier responsibilities, exit arrangements and how changes will be approved.

In practice, a standardised workload with well-understood security requirements may fit a public cloud service, while a highly specialised or tightly controlled system may justify a dedicated environment. A business with a mixture of both may need hybrid cloud, provided it has the skills and governance to manage the additional integration. The right answer can therefore be a defined combination of models rather than a single choice for the whole organisation.

S2 Technology Group can help a business assess its existing systems, identify suitable cloud arrangements and plan the management, security and connectivity requirements around them. The objective is to select an architecture that is supportable and appropriately controlled, rather than moving workloads to the cloud without first understanding their dependencies and responsibilities.