Software Development Life Cycle

Understanding Software Development Life Cycle

When it comes down to streamlined development, clearly defined process and consistent methodology are two prime factors involved in getting from one point to another. Even if you are just starting in the world of development, you must first understand Software Development Life Cycle – SDLC.

Software Development Life Cycle is the stepwise process of developing a well-designed software. It provides a long-term view of software like a product i.e. from basic planning through maintenance and eventual retirement of the developed application. Many organizations, big and small, strive to instantly and efficiently develop high-quality software following intricate planning, generally known as Software Development Life Cycle steps.

There are different models and phases of SDLC that we will be discussing in this post. But first, let us have a look at how SDLC works.

The Work of Software Development Life Cycle – SDLC

Software Development Life Cycle works by lowering the software development cost while simultaneously enhancing quality and reducing production time. If you are wondering how this is achieved then SDLC fulfills these divergent goals by simply following a plan that eliminates the typical pitfalls related to software development projects.

This intricate plan initiates by evaluating the current system for deficiencies. Then, it defines the new system requirements. Further, it creates the software by going through different stages such as design, development, testing, and deployment. When you anticipate costly mistakes such as failing to ask suggestion from the end user, SDLC can eradicate after-the-fact fixes and redundant rework.

As we now know the workings of SDLC, let us have a look at different methodologies used for this purpose.

Software Development Models

Here are some of the most frequently used software development methodologies:

Waterfall Model:

This is the most straightforward and oldest SDLC model. In this methodology, you first finish one phase and then initiate another. As the name suggests, each of the phases contains its own micro-plan and every phase ‘waterfalls’ into another phase. Indeed, the biggest drawback of applying the waterfall model is that even some small details which are left incomplete can halt the whole process. There is no requirement to consider the past issues that can possibly arise in the next phase.

Agile Model:

The Agile model divides the product into various cycles and delivers a functional product quite instantly. This model generates a succession of releases. When each release is tested, it feeds back info that is then incorporated into another version.To speak of the drawback of this model and as Robert Half suggests, during this model, the intensified emphasis on consumer interaction may lead the entire project in a totally wrong direction in a few cases.

Iterative Model:

Iterative model, as the name suggests, emphasizes repetition. In this model, software engineers developed a software version instantly and for apparently little cost, then the version is tested and improved through successive and rapid versions. The biggest drawback in this model is that, if it is left unchecked it can instantly eat up resources.After every iteration, the development team can work on risk management while preparing for the next iteration. Since a cycle involves a small portion of the entire software process, it becomes easier to deal with the development process but it takes more resources.

V-Shaped Model:

This model is referred to as an extension of waterfall methodology. The SDLC model tests at every development stage. Just like a waterfall, the process of the V-shaped model can easily run into roadblocks. The model utilizes a V-shaped model that usually focuses on validation and verification.The biggest advantage of V-Shaped Model is that you can test the software at every stage and in a reverse manner. This is unlike the waterfall model where if the previous stage is finished, then you cannot go back to fix what’s went wrong.

Big Bang Model:

This is a high-risk Software Development Life Cycle model that throws the majority of its resources towards development and is great to use for small projects. However, it lacks the detailed requirements definition stage. It is the simplest model and requires less planning yet lots of funds and programming.

Spiral Model:

This is one of the most flexible Software Development Life Cycle models and is similar to the iterative model in terms of emphasis on repetition. This model passes through the planning, build, design and test phases again and again, and with steady improvements at every step. Spiral Model takes into account the risk that often goes unnoticed by various other models.

DevOps:

This model is the combination of development and operation functions and enables you to build a framework that is focused on communication and collaboration. Its purpose is to automate processes and bring in an environment that is focused on continuous development. 

Phases of the Software Development Life Cycle

A strong SDLC strategy offers high-quality software, reduced resources and time, and less vulnerability. It is not just aimed at maintaining and developing software, it also delivers benefits when it’s time to decommission the code. Here are the phases involved in the Software Development Life Cycle. Let’s discuss each of these phases separately in detail.

Phase 1 – Plan

Just like any other project planning, the foremost step in the SDLC is to map out the complete planning process. In this phase, the organization identifies the content, release theme and timeline. Typically, this involves activities like gathering end-user requirements, ascertaining user stories and release dates planning.

Some of the main points to consider during this phase include:

• To make sure application fulfills business requirements
• Engage in threat modeling or secure design
• The choice of libraries and language to be used in the whole development process
• Mapping test  cases to functional and business requirements

This is the stage to ascertain the new software requirements along with its cost. This phase also details the involved risks and offer sub-plans to soften these risks. Who will use the system? What data will be the input into the system and what data must be the output of the system? These are some of the questions to be answered in this phase.

Phase 2 – Code & Build

This phase involves the actual engineering as well as the writing of the application. All of this is done while attempting to meet the requirements established throughout the planning process. Before the writing, the team analyzes if the software can fulfill all user requirements. In other words, this phase is about determining if the project is practical, financially and technologically feasible for an organization to develop. For this, developers use different algorithms to conclude the software project feasibility.

Some of the main points to consider during this phase include:

• Training of developers in terms of secure coding
• Fixing and finding defects and other security vulnerabilities in software code, while writing it.
• Secured use of open source components
• Cutting down unproductive time, developers usually spend while waiting for the test results.

In this phase, the code is built and integrated. This is the prime focus of the developers and it is one of the longest phases of the entire Software Development Life Cycle.

Phase 3 – Test

This is the phase that can make or break the steps taken in previous phases. In this phase, the QA engineers test the code in terms of requirements to ensure that the product is properly addressing them and performing as expected. In this phase, all types of testing are conducted including UX testing, performance, and functional testing.

Some of the main points to consider during this phase include:

• Application testing for security policy by using different testing methods.
• Conducting a comprehensive and complete array of the functional unit, performance, and integration testing by using similar protocols and language of systems being tested.

Phase 4 – Deployment

In this phase, the software engineers deploy the developed software. This is the release phase, in which software is deployed on production servers. This includes managing, packaging, and deploying various complex releases throughout different environments including clouds and private data centers as well as public cloud resources.

Some of the main points to consider during this phase include:

• Tracking the release progress including its components
• Going away from manual processes of a release towards an automated process in which releasing software usually relies on a business decision.
• The inclusion of security testing as one of the aspects of final quality checks.

During this deployment phase, the developed software gets tested for adaptability and portability and integration related problems so that they can be fixed instantly and without going further. The complexity of the deployment is usually ascertained by the project size.

Phase 5 - Maintenance

In this phase, the developed product is used by the customers. This phase involves the monitoring and maintenance of the application and its performance. It is critical to provide best user experience and to ensure ongoing improvement. To make operational data available to testers and developers, an organization creates feedback loops.

The main points to consider during this phase include:

• Continuous testing and monitoring of applications in the production phase
• Re-assessment of applications for security, performance and user experience as they are changed or updated.

Needless to say, the newly developed software should be evaluated exhaustively for stability and performance. For this, organizations use APM (application performance management) as well as logs and other similar metrics-gathering tools. If any concern is reported, the development team takes that up for remediation in patches or as ongoing software maintenance efforts. The phase confirms the functionality of the software in terms of fewer errors and more efficiency.

Advantages of Establishing Software Development Life Cycle

In the present time, the increasingly complex environment of software development requires comprehensive and elegant solutions. This means that developers need to juggle with several tools as well as technologies while generating code that would perform the efficient level of digital business.

Furthermore, teams need to address a range of issues, including mobile, coding to APIs and cloud environments. There are many tools which lack the flexibility needed for developers and several come with a steeper learning curve.

Thus, it is highly essential to fully adopt tools which detect application security vulnerabilities and incorporate metrics and risk data in a more automated fashion. Any organization that strives to adopt an integrated approach to build protection and security into their SDLC, reduces risk, speed development while reducing costs.

They continue to develop better and new applications while continuously updating current software without compromising on security. In other words, an organization achieves the best level of protection. Nonetheless, SDLC when done right can enable the highest level of documentation and management control.

Developers recognize what they need to build and why. Every involved party can agree to the goal up front and recognize the definite clear plan to arrive at the goal. Everyone knows the resources and costs required.

However, there are many pitfalls that may turn a Software Development Life Cycle implementation into a roadblock to develop than a helping tool. Failure to consider the needs of all users, customers and stakeholders may result in an improper and poor understanding of the system requirements at the outset. In other words, the SDLC benefits only exist when the complete plan is executed and followed faithfully.