How did Waterfall methodology emerge from the software engineering field?

Waterfall methodology emerged in the 1970s from the software engineering field, evolving from manufacturing and construction models where sequential processes were standard. Introduced by Winston W. Royce, it formalized a structured approach to software development with distinct phases: requirements, design, implementation, testing, and maintenance. Waterfall's emphasis on upfront planning and documentation provided a systematic way to manage complex software projects.

This is the key piece of information that I want for today. It's the purpose of having both Waterfall and Agile in my model of management and how to update our mindset.

The word waterfall does not appear in Royce's paper, so the direct attribution here is incorrect. However, the graphics in the paper do visually represent a waterfall. It is easy to understand why people would generally attribute the pattern as a "waterfall" even though the origin of the use of the word is not attributable to Royce and is generally unknown. But as with many things in culture, people's perception and consumption of the article has led to the common reference of Royce's model as waterfall, or "phase-gate." Interestingly, Royce also introduced iterative design and development in the same paper. Fowler has some deeper thoughts, of which most I agree. https://martinfowler.com/bliki/WaterfallProcess.html

I understand that the Waterfall methodology emerged from the manufacturing and construction industries, where sequential processes were the norm, and was later adapted for software development in the 1970s. I recognize that Dr. Winston W. Royce's 1970 paper, often cited as the origin of Waterfall, was actually describing flaws in sequential development, but ironically became the basis for the widespread adoption of the model. I'm aware that Waterfall gained popularity due to its straightforward, easy-to-understand structure, which aligned well with traditional management approaches and the need for extensive documentation in early software projects.

To my knowledge the origin of waterfall methodology, often considered the traditional or sequential approach to software development, originated in the field of software engineering in the late 1950s and early 1960s. The term "Waterfall" was first introduced in a paper titled "Managing the Development of Large Software Systems" by Dr. Winston W. Royce in 1970. In Royce's original model, the development process was depicted as a linear and cascading flow, resembling a waterfall. The model outlined a series of distinct phases that had to be completed sequentially, with each phase building upon the deliverables of the previous one. The defined phases typically included requirements, design, implementation, testing, deployment, and maintenance

I believe one of the advantages of Waterfall is the Milestone or Sign-off events at the close of each stage, that is what specifically Customers liked as signs of progress and whether the project was on schedule, it also provided vary convenient points where the project team could invoice for activities completed.

Waterfall may give an illusion of progress and control, however that often turns out to be a fallacy. Because testing is one of the last phases, defects may only be uncovered late in the process. This can be exacerbated if development teams have come under pressure to meet deadlines and cut corners. Depending on the severity of the defects, this may lead to delay and cost overruns, or even cancellation of a project that has already had considerable sums spent on its development.

The Waterfall methodology gained popularity in the software engineering community and various industries for several reasons: The linear and well-defined structure of the Waterfall model appealed to organizations seeking a structured and systematic approach to software development. It emphasized extensive documentation at each phase, providing a clear record of requirements, design specifications, and testing procedures. This documentation was seen as a valuable asset for project management and future maintenance. The sequential flow of phases provided a straightforward and easy-to-understand framework for project planning and execution. Each phase had distinct deliverables and milestones.

During the 1970s and 1980s the waterfall methodology gained popularity for handling scale intricate projects requiring top notch reliability and quality such, as in defense and aerospace sectors. It offered an approach to software development management with outlined outcomes, milestones and documentation. This method harmonized effectively with project management standards like PMBOK and CMM. Clients and stakeholders appreciated it because it enabled them to track progress at each phase and exert influence, over the projects extent and finances.

Agree with these limitations, especially as related to the large ERP projects we did in the 90s & 00s. It's not reasonable to believe that requirements defined at one period of time will not change 10 months later when we finally got to Integration or End-to-End test. Waterfall struggles in a dynamic, quickly changing environment.

I am a big fan of waterfall, not because it is the best methodology. I have seen as many failures as successes using it. In other methodologies testing is not taken as seriously as it is in Waterfall. It makes me sick how we constantly dole out systems that are inaccurately developed because we ignore testing or testing outcomes.

However the Waterfall approach encountered obstacles. Received criticisms, particularly, during the 1990s and 2000s with the emergence of new technologies, markets and evolving customer expectations. It was criticized for being too rigid, slow and not adaptable enough to meet the uncertain demands of software development. The Waterfall method operated under the assumption that project requirements and designs could be fully defined and locked in at the projects onset resulting in flexibility for changes that were deemed costly. Additionally it overlooked the significance of feedback mechanisms and collaboration, between developers and clients as the necessity of regular testing and validation procedures.

Over time, the Waterfall methodology has seen limitations, including: The rigid sequential nature of Waterfall made it challenging to accommodate changes in requirements or address issues that emerged late in the development process. Clients often had limited involvement until the testing phase, leading to potential misunderstandings and dissatisfaction with the final product. Waterfall projects tended to have long development cycles, and clients had to wait until the end of the process to see a working product. The approach did not handle uncertainties and risks well, as it assumed that all requirements could be gathered and understood upfront.

The Waterfall methodology struggles in fast-changing environments due to its rigid structure. It assumes all requirements are clear upfront, making it hard to adapt when things change mid-project. Feedback comes too late, often during testing, leading to costly fixes or missed expectations. Its long phases delay delivering value, leaving stakeholders waiting. This lack of flexibility and real-time collaboration makes it a poor fit for dynamic projects, paving the way for Agile’s iterative, customer-focused approach. Still, Waterfall can work well for stable, predictable projects.

I've found, in many but not all situations, that developers will use Agile as an excuse to not gather requirements - they claim requirements get sorted out during the sprint iterations. I think this is a huge mistake. The most success I've had w Agile is treating it as a LOT of mini-waterfalls.

Customer requirements and technology changes more and more quickly. I think Waterfall will fail more than not because it tends to not move fast enough.

As the limitations of Waterfall became apparent, alternative methodologies emerged, including: Iterative approaches, such as the Spiral model, allowed for repeated cycles of development and refinement, incorporating feedback and adapting to changing requirements. Agile methodologies, like Scrum and Kanban, prioritized collaboration, adaptability, and incremental delivery. They emphasized responding to change and delivering value early and often. DevOps practices integrated development and operations, fostering continuous integration, continuous delivery, and collaboration between development and IT operations teams.

After encountering the drawbacks of the Waterfall approach software developers started delving into methods such, as Agile, Scrum, Kanban, Lean, Extreme Programming and DevOps. These methodologies emphasize flexibility, teamwork, meeting customer needs and ongoing enhancements. They roll out software updates in increments regularly while integrating feedback and modifications during the process. This fosters a dynamic team environment where developers and clients collaborate as allies, than opponents.

I'd disagree that the future of Waterfall for stable, low complexity, long projects - I'd question the ROI of a project like that. I believe the future of Waterfall is in very short projects with well-defined requirements that can be completed in 3-4 months. I also believe Agile sprints should be mini-waterfalls.

Scrum is probably the future of project implementation. However you cannot just use a piece of a methodology and say you work it. As Joe Carey stated, many developers and major corporations only utilize Agile elements without the whole methodology, whether Scrum, Kanban, Lean, etc... If you do not utilize all aspects of the sprint then no methodology will work.

In the current software development landscape, Waterfall is still used in certain contexts, particularly in industries with strict regulatory requirements or projects where a highly controlled and predictable process is essential. However, its usage has diminished in favor of more agile and adaptive methodologies.

The Waterfall approach remains popular in sectors such, as healthcare, finance and engineering due to its emphasis on stability and compliance. It is best suited for projects with defined requirements, complexity and extended timelines. However it has adapted over time to address emerging challenges. Nowadays many professionals combine Waterfall with methods to form solutions. This involves utilizing Waterfall for the stages of planning and design while employing practices, for development and testing phases. This blended approach allows teams to tailor their strategies to meet project requirements and objectives effectively.

As Waterfall's founder, DR. Winston W. Royce, mentioned his experience, he used this methodology to develop software for spacecraft mission planning. This method would still be relevant for similar projects where accuracy is essential, and there is less flexibility on a budget and human resources.

The future of Waterfall methodology is likely to be niche, catering to specific industries and projects where its structured and predictable nature aligns with requirements. However, the broader trend in the software industry continues to favor agile practices, DevOps, and iterative development approaches.

The traditional waterfall approach remains relevant, in contexts despite the evolution of software development practices. Incorporating elements from methodologies can enhance the effectiveness of solutions providing benefits to customers. Prioritizing a customer approach and embracing feedback are essential for ensuring software products align, with user requirements and preferences.

As noted in my notes above, I've had success integrating Agile & Waterfall by treating a sprint as a mini-waterfall. High level requirements need to be gathered to understand effort & complexity for backlog grooming & sprint planning; dev & unit test during the sprint; then capacity in subsequent sprints should be reserved for re-work on features/stories that don't pass unit test. Every couple sprints there needs to be an Integration test sprint.

The traditional waterfall approach remains valuable, in projects that prioritize stability and predictability. Nonetheless it's crucial for it to adapt and blend with methodologies to remain pertinent, in the evolving realm of software development. Embracing a customer focused perspective and emphasizing feedback can enhance the flexibility and efficiency of the waterfall method guaranteeing that the end product genuinely satisfies user requirements. Integrating the advantages of both Waterfall and Agile approaches can result in improved project results.

Reflecting on Joe. What you described is not really "integrating" agile and waterfall just doing agile the proper way. I think it is one of the most common myths that in the case of agile you shouldn't plan. Actually, the opposite is true.

Dr. Winston Royce presented a seminal paper in 1970 at IEEE WESON called “Managing the Development of Large Software Systems”. If you only read the first two pages (especially figures 1 & 2) you get the legacy waterfall development approach description. Most people never made it to page three were he said “Figure 3. Hopefully, the iterative interactions between the phases is confined to successive steps.” Then “Figure 4. Unfortunately for the process illustrated, the design iterations are never confined to the successive steps.”. So he actually described and recommended iterative development yet he’s credited for creating waterfall (admittedly it is a simpler approach, just not the right one for most situations.)

As I gathered from a discussion in the past... the feedback loop on the chart, between phases, is overlooked completely, making it a uni-directional monolith approach