The waterfall methodology is a traditional and sequential system deployment methodology. It follows a linear and rigid process of phases, such as requirements, design, development, testing, and deployment. Each phase must be completed and approved before moving to the next one. The waterfall methodology is suitable for simple and well-defined projects with stable requirements and minimal changes. However, it can also be inflexible, slow, and risky for complex and dynamic projects with uncertain requirements and frequent changes.
As processing power increased in the 1990s, but projects were heavily staged in Waterfall, the Agile Manifesto was launched in 2001. The manifesto is: Individuals and interactions over processes and tools. Working software over comprehensive documentation. Customer collaboration over contract negotiation. Manageable, smaller development phases called "sprints" or iterations, which typically lasts 2 weeks were introduced. Agile is dynamic, flexible and allows a lot of collaboration between developers and the stakeholders. It lends itself to more complex projects, where requirements evolve quickly. In my career, I never worked with Agile but working with apprentices over the years, I can see the benefits.
The agile methodology is a modern and iterative system deployment methodology. It follows a flexible and adaptive process of cycles, such as planning, analysis, design, development, testing, and deployment. Each cycle is called a sprint and usually lasts for a few weeks. The agile methodology is suitable for complex and dynamic projects with changing requirements and feedback. It allows for faster delivery, higher quality, and more customer satisfaction. However, it can also be challenging to manage, coordinate, and document in large and distributed teams.
DevOps is an amalgamation of developement and operations. The DevOps team's focuses on delivering a collaborative solution to change control/release control/version control. It promotes the concept of Continuous Integration/Continuous Deployment. For it to be successful, there has to be a cultural change (traditionally it was an 'us' and 'them' environment between the development team and operations).
The devops methodology is a cutting-edge and collaborative system deployment methodology. It follows a continuous and integrated process of development, testing, and deployment. It aims to bridge the gap between the developers and the operations teams by using tools, practices, and culture that enable automation, communication, and feedback. The devops methodology is suitable for fast-paced and innovative projects that require frequent updates and improvements. It enables faster delivery, lower costs, and higher reliability. However, it can also require a significant shift in mindset, skills, and processes for the teams involved.
The DevOps methodology is a contemporary approach to system deployment, emphasizing continuous integration and collaboration. It facilitates seamless development, testing, and deployment cycles, fostering communication and automation between developers and operations teams. Ideal for dynamic projects, DevOps enables rapid updates and enhancements, leading to enhanced efficiency, reduced expenses, and heightened reliability. Nevertheless, adopting DevOps often necessitates substantial adjustments in mindset, expertise, and workflows for all involved parties.
The waterfall, agile, and devops system deployment methodologies differ in several aspects, such as the scope, speed, quality, and collaboration of the system deployment process. The waterfall methodology has a fixed and comprehensive scope, a slow and sequential speed, a variable and dependent quality, and a low and formal collaboration. The agile methodology has a flexible and incremental scope, a fast and iterative speed, a high and independent quality, and a high and informal collaboration. The devops methodology has a continuous and evolving scope, a rapid and integrated speed, a consistent and automated quality, and a seamless and collaborative collaboration.
Each system deployment methodology has its pros and cons depending on the project context, goals, and constraints. The waterfall methodology is easy to plan, manage, and document, but it can also be rigid, inefficient, and risky. The agile methodology is responsive, adaptable, and customer-oriented, but it can also be chaotic, complex, and inconsistent. The devops methodology is innovative, efficient, and reliable, but it can also be demanding, disruptive, and challenging.
There is no one-size-fits-all system deployment methodology. You need to consider various factors, such as the project size, complexity, uncertainty, duration, budget, quality, and stakeholders' expectations. You also need to evaluate the capabilities, resources, and culture of your team and organization. You may choose one methodology or combine elements from different methodologies to suit your specific needs and preferences. The key is to align your system deployment methodology with your project objectives and deliver value to your customers.
Waterfall is still relevant for legacy systems or hardware that has embedded software that is unlikely to be changed. An example is X-ray machine software, air traffic control software. My first job was in a software house for the Banking industry. 15 years later, when I was working in an Investment Bank, I met a former colleague who I used to manage. He was there as a contractor, and was working on the same software that I was working on 15 years prior. "There is a saying, if it aint broke, don't try and fix it!"