No system, product, or piece of software comes out of a vacuum, fully-formed. They are a result of trial-and-error, planning, and strategic execution. Sometimes, you can hit it out of the park right away. Other times, you’re saddled with something that took too much time, cost too much, and doesn’t work in the existing market. This is why development teams rely on the product development lifecycle. Nowhere is having a set methodology more crucial than in the IT world.
The Software Development Lifecycle (SDLC) is a framework that’s used by development teams to produce high-quality software products in an organized, systematic, and cost-effective manner. It takes the software building process and breaks it down into a series of phases or steps that provide a common understanding of the various components of the project. This way, each part flows into the next, and there’s no danger of forgetting a step.
But, depending on the project’s context and the business requirements, the project manager will need to determine which SDLC model their software engineers will utilize. Each has its own advantages and disadvantages, and it’ll depend on the specific concerns and requirements of the project.
Here are the key pros and cons of the most common SDLC methodologies.
Waterfall Model - this sequential model is the one of the oldest and most straightforward of the linearly-structured methods. It’s based on 5 phases: Requirements, Design, Execution, Testing, and Release. Engineers finish one phase, then move on to the next. There is no moving backwards, and each stage relies on information from the previous stage. This method is easy to understand and to manage.
One of its major drawbacks, however, is its lack of flexibility. Delays can throw off the entire timeline, and there is little room for revision once a stage is completed. You’d have to wait to address problems until you get to the final maintenance stage, which potentially presents issues for longer-term projects.
V-Shaped Model - This is better known as the Verification and Validation model. This grew out of Waterfall and is notable for having a corresponding testing phase for each development stage. LIke the Waterfall, each stage begins once the previous one has ended.
This model is useful when there are no surprises or unknown elements, but it’s still difficult to go back and make changes once a phase is complete.
Iterative Model - This model is all about repetition. Instead of starting with a full list of completely realized requirements, this model lets you implement a set of given requirements, test them, and then pinpoint further requirements upon evaluation. A new version of the software is produced with each phase--hence ‘iteration.’ You then essentially rinse and repeat until your complete system is ready.
The advantage of this model is that it gives you a working version early in the process and makes it less expensive to implement changes. On the other hand, resources can be quickly eaten up by repeating a single process over and over again.
Spiral Model - This is one of the most flexible SDLC methodologies, taking its cues from the Iterative model and its reliance on repetition. Here, the project passes through 4 phases over and over again in a “spiral” pattern until completed. This allows for multiple rounds of polishing and refining.
While this model can be great for building a highly-customizable product (one that can incorporate user feedback early on), it also runs the risk of creating a never-ending spiral of revisions and updates.
Big Bang Model - This one is a bit of an outlier when it comes to SDLC methodologies. The Big Bang follows no specific process, and has very little focus on planning. It basically starts from nothing, and through a rapid expansion of code, a product appears relatively quickly. Typically, this is used best when it’s a small project with 1-2 software engineers and a client who doesn’t really have a firm grasp on all the requirements just yet.
This method isn’t recommended for overly large or complex projects, as it’s intensely high risk. If enough of the requirements aren’t understood from the beginning, then the finished product may or may not be what the customer needs or wants--at which point you have to start again.
Agile/Scrum Model - This model is our sandbox. Here, the product is broken into cycles that promote continuous iterations of development throughout the lifecycle of the project. Development and testing activities are done concurrently, resulting in ongoing releases, each with an incremental change from the previous release. At each iteration, the product is tested.
This model emphasizes interaction between the customer, developers, and testers to continuously improve the product. Since the methodology is less directed than some of the others, it can sometimes get stuck or go off the rails. By the same token, all the unique interactions make it difficult to accurately estimate the development timeline.
Choosing the right model can be one of the most challenging parts of a software development project, and there’s really no right answer. There’s really no set criteria for small and large organizations to use in selecting a methodology, and several SDLC models might be a fit for any given project. Oftentimes, a hybrid of more than one approach can be the way to go. At Intertec, for instance, we’ve had great success coming Agile and Waterfall into a methodology we refer to as Jaglion.
Given the fast-paced, results-now nature of the world, a nimble, transparent, and flexible approach will probably offer you the best chance at hitting all of your KPIs.
Choosing the Right Software Development Life Cycle Model
Whether you’ve been in the business for a while or are just starting out, it’s still a valuable experience to critically analyze the various methods and apply a systemic approach.
- Learn about the SDLC models. It’s best to have all the tools and information at hand in order to make an informed decision. If you know them already, it doesn’t hurt to review.
- Assess the needs of the stakeholders. By understanding the business landscape, stakeholders’ concerns and requirements, business priorities, technical capability and ability, and technological constraints, you can easily narrow down which SDLC fits their criteria.
- Define your criteria. Some questions you can ask are:
- Is the SDLC suitable for the size of your team and their skills?
- Is the SDLC suitable for the selected technology you use for implementing the solution?
- Is the SDLC suitable for client and stakeholders concerns and priorities?
- Is the SDLC suitable for the geographical situation (e.g. a distributed team)?
- Is the SDLC suitable for the size and complexity of your software?
- Is the SDLC suitable for the type of projects you do?
- Is the SDLC suitable for your software engineering capability?
- Is the SDLC suitable for the project risk and quality insurance?
- Now, it’s time to decide. Once you’ve defined the criteria and discussed it with the team, it might help to create a decision matrix that gives your criteria a defined weight and score. This should make it easier for you to settle on a decision.
- Be flexible. You might start the project aligned with one modality, but as changes and updates occur, you might need to pivot to a different model. Again, some companies create their own hybrid SDLC models and tailor them to their organization structure.
How Do You Measure the Success of Your SDLC Methodology?
Ultimately, your software project needs to be delivered on time, on task, and at the highest level of quality. What that means is that your processes and methodology should allow you to minimize your risk, manage issues before they happen, and control costs along the way. How do you do that? Simple, you rely on something that offers predictability and is inherently adaptable to any changes or issues along the way.
Therefore, you can easily rule out some of the more common systems listed above. On their own, some of the more rigid SDLC frameworks (such as Waterfall or V-Shaped) don’t allow the transparency and flexibility to alter things on the fly. While these are great for departmentalization and executing a specific plan, you end up getting locked into your production journey if you don’t incorporate tactics from other methodologies. The result is that you can only hope against hope that the outcome in the end is favorable to you, your client, and your bottom line.
On the other hand, Agile and Spiral allow you the freedom to make tweaks and incorporate feedback, so that there are no surprises and all outcomes can be clearly managed. For us at Intertec, we like to be able to decisively manage risk. A successful model manages all the knowledge at hand and keeps a tight hand on the reins of the project, while hitting all the KPIs. More importantly, the right model is adaptive to the product’s demand, which almost always ends up as a win for both us and the client.
Learn More About About Intertec's IT Program & Project Management Services:
At Intertec, we pride ourselves on our professional program and project management principles, and we leverage our entire knowledge base into the projects we manage. This means that we listen to our customer’s specific needs and requirements, and build out an SDLC methodology that’s based on key industry standards. We prioritize the scope, time, quality, and cost, and offer a team of project managers that are Agile experts, who rely on over 30 certified SCRUM Masters.
Our team is hyper-aware of all the phases of a project, from assessment to implementation, and we tailor our specific approach to have a hands-on feel. This way, all the particular elements of a project are addressed and we guarantee the successful achievement of the agreed upon solution.