More and more companies are choosing to run their applications in the cloud. Migrating an application to the cloud is a significant undertaking that requires careful planning and execution. In this blog post, we present a six-phase guide to cloud migration, illustrated through the example of migrating an application to a Software-as-a-Service (SaaS) solution. We highlight the key components and steps of each phase. The goal of this approach is to ensure a target solution in the cloud that meets the specific requirements of the organization.
Initial Situation
An increasing number of companies are migrating their applications to the cloud, replacing and modernizing their existing on-premises infrastructure. Over the past few years, many security standards have been established, and the security level of cloud providers has improved—making cloud migration more attractive for many organizations.
But how should the migration be approached to ensure the target solution in the cloud meets not only functional and security requirements but also compliance standards? And how can it be seamlessly integrated into the existing IT landscape (both on-prem and cloud)?
Six-Phase Migration Guide
To address these questions, we present a six-phase guide to cloud migration designed to ensure the cloud solution meets all organizational requirements.
Below, we examine each phase in detail and explain the key components and steps. We also highlight critical aspects that should be given special attention in each phase.
Phase 1: Current State and Requirements Analysis
The first step in any cloud migration is analyzing the current state and requirements. This involves a detailed assessment of the application, data assets, and business processes. It’s essential to identify and document existing applications, dependencies, and data.
Key components:
- Inventory of current IT infrastructure
- Identification of application functions, data, and data classes
- Determination of regulatory and legal requirements (e.g., GDPR)
- Evaluation of current security measures
A crucial aspect of this phase is the security analysis and the resulting security requirements. The project team should identify existing vulnerabilities and assess them as part of a comprehensive risk analysis.
Phase 2: Target Concept
Based on the current state analysis, a target concept is developed that defines the future cloud architecture and the requirements for the cloud application. Common cloud security measures should be established and considered.
Key components:
- Selection of cloud provider and target architecture, including necessary interfaces
- Provisioning of required cloud functions
- Central security requirements and measures
- Operations and maintenance concept
- Monitoring tools (e.g., for service tracking and cost control)
The target concept serves as the foundation for the following phases and ensures that all requirements for the new environment are clearly defined. The project team should also ensure compliance with established internal security standards.
Phase 3: Cloud Setup
Once the target concept is finalized, the cloud environment is set up. This includes configuring the cloud infrastructure, implementing security measures, and performing an initial data transfer. While many cloud providers offer tools to meet security and compliance requirements, these often need to be activated or customized by the customer.
Steps:
- Setup of cloud infrastructure and application
- Activation of licenses and tools
- Configuration of functions and interfaces
- Implementation of security configurations (e.g., firewall, encryption, access rights)
- Data transfer
Security measures should follow company-wide standards. Additional recommendations, such as those from the German Federal Office for Information Security (BSI), may also be applied. A “security-by-design” approach is essential—security mechanisms should be integrated from the beginning.
Phase 4: Testing / Pilot
After setup, the cloud environment must undergo thorough testing. Depending on the complexity of the application, a pilot phase may be appropriate. The goal is to identify and resolve issues early.
Steps:
- Define test cases based on application scenarios (use cases)
- Test use cases, performance, and security
- Evaluate tests and adjust configurations
- Fix defects and issues
Test cases should cover both regular and exceptional scenarios to provide a comprehensive picture. All relevant stakeholders should be involved in the testing process.
Phase 5: Migration
This phase completes the remaining data migration and transitions the application to the cloud. To minimize risks and downtime, the transition may be carried out in stages.
Steps:
- Prepare application and data for final migration
- Conduct employee training
- Execute data migration and updates
- Monitor migration and resolve issues
Maintaining data integrity and security during migration is critical. Appropriate tools and secure transmission paths should be used.
Phase 6: Handover to Operations
After migration, the application is handed over to the internal or external operations team. Even after successful migration, the cloud environment should be continuously monitored and optimized. Operating costs and security should be regularly reviewed.
Key components:
- Transfer of documentation to operations teams
- Initiation of support and hyper-care teams
- Audits and security checks
- Continuous monitoring and optimization of the cloud environment
Conclusion: Cloud Migration of an Application
Migrating to the cloud is a complex project that demands precise planning and careful execution. By adhering to proven security standards, a secure cloud environment can be established that meets the specific needs of the organization. Each of the six phases—from analysis to operational handover—plays a vital role in ensuring a successful and sustainable cloud migration. Collaboration across all teams and departments is essential to achieve a successful outcome.
