Waterfall vs. Agile Development Models in Software Development

Waterfall vs. Agile Development Models in Software Development

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What is a development methodology?

Development methodologies are chosen plans that project managers implement to establish the tasks at hand, how those tasks are organised and then how they should be executed. Project managers usually choose between Waterfall and Agile development models to develop and structure these ‘plans’. A hybrid approach, and the applicability thereof at SovTech, in addition to these two methodologies will be explored below.

Waterfall and Agile Development Models – The comparison

An agile development methodology is used by project managers when applying and following a repetitive or interactive process. Basically, breaking the project down into smaller parts and tasks that will be completed in shorter time periods. This method is usually adopted in software development because of the rapidly changing industry. In contrast waterfall development methodologies are focused on a sequential process and follows a more rigid structure. This is because they concentrates on completing each phase fully before moving onto the next step of the project.

Why do we usually pick one over the other?

Like the model displayed above, the waterfall methodology is phase orientated. Therefore, this approach is chosen when tasks can be broken down and each completed before moving onto the next one. The stepped process helps the project manager separate these tasks in alignment with a fixed timeline and cost structure.

Reasons why the waterfall methodology is advantageous:

• The full scope of the project is outlined before it even begins – creating a structured and holistic overview. There is therefore, very little room for error.
• It allows the team to share the workload, providing enough time for the members to work on other projects simultaneously.
• The client is not as involved because the guidelines and parameters are set in the earlier phases. With the end goal consistently in mind there is very little need for constant client interaction.

Drawbacks of the Waterfall Methodology

• The inability to make significant changes. It’s impossible to revisit a phase once it is completed. Should there be a need to make a change, the process would possibly have to restart.
• The project could be experience major delays as the testing phase occurs near the end of the process. Because of the model, the next phase can only start after all the tests have been completed.
• There is a high risk of the final product not meeting the client’s expectation, and the final product being redundant.
• In short, “If the ladder is not leaning against the right wall, every step we take just gets us to the wrong place faster” – Stephen R. Covey.

Essentially, the Waterfall Model is applied when the project is clearly defined, there isn’t a need for significant change and there’s a fixed time and budget. Agile Models are developed when a project is interactive and increment focused. What this means is that the project is broken into smaller, more frequent deliverables, with an idea of the final product in mind. Until the final product is produced, these deliverables are under constant revision.

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Why this method is held in such high regard in software development:

• It is easily adaptable and encompasses all possibilities of change. With constant moving pieces, this approach is flexible enough to quickly adjust to the new requirements.
• Sprints promote frequent testing and don’t require specific phases to allow the product to be revised – this ensures consistency throughout.

• At the end of every sprint there is a deliverable. This not only ensures that the project stays on track, but allows smaller, more frequent versions to be released – always having something to offer.
• This also encourages constant client feedback. Client happiness and problem fixing, is the greatest importance.

Choosing to follow the agile development model is therefore preferred when rapid production is the key to success, when the variables and environment are constantly changing, and when the final product is unclear and comes about from the completion of each sprint.

Is it possible to combine the two models and create a Hybrid Development methodology?

Absolutely. This hybrid approach was created to capture ‘the best of both worlds’. Following the “Water-scrum-fall” model, as seen below, the agile or scrum model is injected into a more loose waterfall model.

”Water-scrum-fall” – Agile Waterfall Hybrid Model

This approach uses Waterfall and Agile Development Models and is designed to combine the benefits and try to eliminate the drawbacks that the models create independently. This is accomplished by:

• Collecting all the requirements and necessary documentation, before moving onto the next phase of designing the product – following the Waterfall methodology.
• The project manager will then follow an agile methodology where the product enters the iterative process of; development, testing and feedback in a sprint format.
• On sprint completion, the final phases of product deployment and maintenance, from the Waterfall methodology, are then executed.

This method, that uses Waterfall and Agile Development Models is best suited for situations where project requirements are constantly and rapidly changing – the sprints providing the environment to do so – but an accurate estimation of budget and time is of high importance- highlighted by the traditional model’s initial and ending phases.

Even though project managers use this approach to try to increase the speed, decrease the cost and increase the quality of the project and product offering, it is possible that following two methods ‘simultaneously’ can become confusing and the steps could become unclear – providing little constructive structure – compared to picking and implementing one development methodology.

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Which approach does SovTech take and how do we implement it?

SovTech, as a custom software development company, takes pride in delivering a unique product in the fastest way possible. Working in the tech industry, however, can make this complicated as variables are always changing. In tech, “if you’re not first, you’re last” – this saying resonates throughout the company and highlights the importance of why we have adopted the overall model of agile development. This is clearly seen in two of the Business Units, however Product Labs (another business unit within SovTech) has cleverly decided to use the waterfall model in addition to the agile model.

This approach has been decided upon as it has proven to not only add value to our partners by ensuring the freedom and opportunity for change, but the promise of a deliverable within a fixed time period and budget – an agile hybrid approach if you will. Essentially allowing our partners to be content in knowing that the risk lies heavily in our hands, that their product is on the fastest route to market, is constantly exposed to new solutions and is consistently improved by an incredibly dedicated development team.

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Conclusion

The choice to use Waterfall vs. Agile Development Models is based on the requirement of the project which inherently selects which model would be best for it. Therefore, once the decision to utilise an Agile, Waterfall or Hybrid development methodology has been made, the process can be refined to best fit the project goals. Ultimately, the way the work is completed is of great importance. However delivering a solid and maintainable product that satisfies the customer is what really counts.

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