How do system architecture lifecycle models integrate with software engineering processes?

1 Waterfall model

The waterfall model is a linear and sequential approach to system architecture and software engineering. It consists of several phases, such as requirements analysis, design, implementation, testing, and deployment, that are executed in a fixed order. The output of each phase serves as the input for the next phase, and no phase can start until the previous one is completed. The waterfall model assumes that the system architecture and the software requirements are stable and well-defined from the beginning, and that changes are minimal and costly. The waterfall model is simple and easy to follow, but it can be rigid and inflexible to accommodate changing needs and feedback.

2 Spiral model

The spiral model is an iterative and risk-driven approach to system architecture and software engineering. It consists of four quadrants, such as planning, risk analysis, engineering, and evaluation, that are repeated for each cycle of the spiral. The output of each quadrant serves as the input for the next quadrant, and the cycle ends with a deliverable or a prototype. The spiral model assumes that the system architecture and the software requirements are dynamic and uncertain, and that changes are frequent and manageable. The spiral model is flexible and adaptable to cope with risks and changes, but it can be complex and expensive to implement and monitor.

3 Agile model

The agile model is a collaborative and incremental approach to system architecture and software engineering. It consists of several iterations, such as planning, design, coding, testing, and review, that are executed in a short time frame, usually between one to four weeks. The output of each iteration is a working and potentially releasable software increment that meets the customer's needs and expectations. The agile model assumes that the system architecture and the software requirements are emergent and evolving, and that changes are welcome and beneficial. The agile model is responsive and customer-oriented to deliver value and quality, but it can be challenging and demanding to maintain communication and coordination among stakeholders.

4 Model-driven architecture

Model-driven architecture (MDA) is a standards-based and platform-independent approach to system architecture and software engineering. It consists of three levels of abstraction, such as computation independent model (CIM), platform independent model (PIM), and platform specific model (PSM), that are derived from each other using transformations. The output of each level is a model that represents a different aspect of the system architecture and the software functionality. MDA assumes that the system architecture and the software requirements can be expressed and manipulated using models that are independent of the implementation technology and platform. MDA is reusable and portable to support interoperability and integration, but it can be abstract and complex to understand and apply.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?