Your Guide to the Software Development Life Cycle

In the fast-paced world of software, it’s hard to believe that the basic development process has been around since the 1950s. 

Sure, we’ve made tweaks and improvements such as creating the waterfall model in the 70s and introducing agile in the early 2000s, but the basic steps of the software development life cycle (SDLC) have remained the same. 

To understand how it’s lasted for so long in an environment of such rapid change, let’s explore what the SDLC involves and the new methodologies that have been layered on top of it over the years.  

What is the software development life cycle (SDLC)?

The SDLC is a seven-phase process used by software engineers to design, develop, and test new software products. The primary objective of this seven-phase life cycle is to help development teams create a high-quality product quickly and efficiently. 

Each phase of the life cycle is focused on creating deliverables that feed into the next stage of development. To keep projects running smoothly, every phase has a clearly defined purpose that contributes to the creation of an error-free end product.  

The Seven SDLC Phases

The SDLC has seven phases. Mastering each stage before moving to the next is key to meeting project requirements and stakeholder expectations. Let’s take a closer look at each of the seven phases.

1. Planning
In this initial stage, the development team is focused on collecting the requirements of the project and analyzing them to create a plan for development. 

TIP: To make this phase easier, many use SDLC project management planning tools. The key is to find one that’s collaborative and flexible enough for dynamic project planning.

2. Feasibility & requirements
In the feasibility and requirements phase, the project team works to get the development project off to a great start. This is when they execute a feasibility study and add the results to a software requirement specification (SRS) document for use throughout the life cycle of the project. 

TIP: Many teams store their SRS document in an easy-to-access and easy to update place such as Google Drive.

3. Design & prototyping
At this stage of the process, developers create a series of prototypes and begin gathering early feedback that informs key technical decisions. The process typically starts with a quick-analysis design that gets continually refined throughout the phase.

TIP: It can be hard to know when to call your prototype ready for the next stage, so make sure to define your goals before you begin.

4. Software development 
The goal of the software development phase is to code a working system that addresses all requirements in the SRS document.

TIP: Review your work early and often. Course correct as needed to keep yourself from working too far in the wrong direction.

5. Software testing
The testing phase is an important part of the process, ensuring the final product is working properly. At this stage, experienced testers verify the software code and programming work according to the current requirements. 

TIP: Some amount of rework will be necessary, so plan for it. Use past projects as a guide for anticipating how long any rework might take.

6. Implementation & integration
At this stage, the software is released into a production environment and installed into a real-world setting where customers can use it and evaluate its performance.

TIP: To streamline this phase, reuse deployment strategies from past projects. This will allow you to build on previous knowledge and better budget and communicate with clients about what to expect.

7. Operations & maintenance
In the operations and maintenance phase, any issues encountered during deployment are communicated back to the development team. Depending on their severity, the team may choose to fix the issue immediately or incorporate it into the next version of the software. 

TIP: Make it easy for your end-users to tell you about their experience. Their feedback will help you prioritize the updates and plan rework to align with other goals.

The SDLC phases described above are applicable to any software development methodology. Each one requires input from developers, project managers, testers, and stakeholders to be most successful. 

Developers should be familiar with each stage of the cycle, even if most of their work focuses on only one of them. Each person involved in the process should understand how they can contribute to improving the process and its outcomes. 

Popular SDLC Methodologies

The SDLC provides a framework to help development teams quickly and efficiently produce high-quality software. A well-performing SDLC will:

• Define requirements of the new system
• Lower the cost of software development cycle
• Account for known pitfalls from past development projects
• Evaluate existing systems for deficiencies
• Anticipate costly mistakes 
• Eliminate redundant work and after-the-fact fixes 
• Improve the quality of the software while shortening production time

Depending on the specific requirements of your project, you may choose to use a different SDLC methodology to achieve them. Popular SDLC methodologies include the waterfall model, spiral model, and the agile model. 

Different methodologies give developers options on how much emphasis they need to place on each phase of the life cycle. The frameworks also dictate exactly how each phase plays into the next and guides the duration of a project. 

For example, a project that needs an expedited development plan might use the agile methodology. But a project that requires thorough documentation might be better off using a waterfall approach. 

Choosing a Software Development Life Cycle Methodology

No matter which methodology is used, the goal is to please stakeholders and produce working software. Let’s talk about how to decide which is right for your project.  

Agile
Agile software development is a fast-paced approach that prioritizes requirements gathering and produces a product quickly. Choose this method if tight feedback loops are important for your project. 

Waterfall
The waterfall approach is a framework that relies on thorough documentation at each stage. You might choose this approach if signoffs and approvals are important to your decision-makers and stakeholders.

Lean
A lean development methodology prioritizes developer efficiency and cuts waste wherever possible. If you’re under timeline or budgetary constraints, choosing this approach will help you meet them. 

Iterative
An iterative framework is one that starts work toward defined needs before they are all understood. This approach works to incorporate additional requirements as they arise. Choose this methodology if your project is not well defined and requires you to learn as you go.

Spiral
The spiral approach is similar to the iterative approach, but in this case, known risks are taken into consideration before the development begins. Use this methodology if your end goal is loosely defined, but the risks are clear. 

DevOps
This methodology has both the developers and operations teams working together, making updates more efficient than with other methods. Choose this approach if you need a robust process to ensure you meet your goals.

Structure for Success

Planning, building, and maintaining a new software system is a complicated process. Our approach can change not just with every project we tackle, but also with every phase of the process.

Thankfully, underneath all of these inconsistencies is a tried-and-true framework that helps us stay on track. Tell us, how do you use the SDLC methodologies to power through your projects?