Software Development Lifecycle Management
Ever since the use of computers became mainstream, software developers have been searching for ways to create a development method that would increase the speed of product development and process productivity. This need lead to the creation of the software development life cycle.
What is Software Development Life Cycle?
SDLC or Software development Life cycle is a process of well-defined steps followed by the software industry to develop high-quality software products exceeding customer expectations and complete within estimated time and budget. It is a detailed plan providing insight on how to develop, maintain, improve, replace, or upgrade software. It provides a well-defined methodology to enhance the quality of the developing process and provide a high-quality output product decreasing the time and cost required.
SDLC splits out the whole single process of software development into different and separate steps enabling the developers to focus on each step separately to come up with a better solution to achieve the target of high quality and cost and time effectiveness. While working in a long single product, a developer may lose the focus in small detail and miss the opportunity for improvement. But dividing the process into small steps helps the developer in maintaining focus while working.
Moreover, if different people are working on different steps, this will help in observing detail with different perceptions and minds resulting in better ideas for improvement. Developers may work on different steps simultaneously, which makes this process time-efficient. SDLC consists of seven phases or steps, including planning, defining requirements, creating design and prototyping, developing software, testing, deployment, and operations and maintenance. Growing companies may merge some of these steps or split these steps into more steps depending on the scope of the product. SDLC defines the tasks performed at each step in the developing process.
Steps of SDLC
The following are the necessary steps of SDCL that ensure the smoothness, efficiency, and productivity of the software developing process.
In this step, the customer is asked to provide the requirement of the project. This may include what the software product is supposed to do or other related info. For example, if a customer wants a social application, one of the requirements of the application will be the ability to send and receive messages to other people. If the product is a media player, then the customer will enlist play, add and open options in requirements. Such requirements may also include the hardware or resources needed to complete the project. For example, if a team is working on a project of application that is supposed to work online, they will need a web domain to connect to the application to make it able to transfer data online. Once all necessary information from the user is received, it is put down formally in a document called Business Requirement Specifications (BRS). This document provides a complete business operations overview and customer requirements. One we have the document finalized, customer requirements are analyzed, and a new document is prepared. The new document describes the complete product changes expected by the customer. This document is called System Requirement Specifications (SRS). It is also referred to as a “parent document” since all future planning and development is rooted in the contents of this document.
Once the System specifications requirements are documented, a thorough plan is made to achieve the target. This plan includes the choice for technology or platforms that best match product requirements, as well as all the equipment or devices necessary. People with suitable skill sets are selected, and a team forms along with the hierarchy and responsibilities of each member. The cost of the required resources is calculated to determine whether this plan is financially feasible. Once the plan’s main points are complete, a detailed timeline comes into play, with milestones that define the time frame for completion. A project timeline is usually planned to keep a check and balance of team performance and pace. It helps in maintaining a good rate and achieve all goals in time. All project risks are also part of the planning stage. Planning experts usually use a set of different development approaches to specify and choose all methods that will work well for a specific project.
Designing / System Architecture
Once the process is planned, and all the requirements are documented, system design is developed. The system architecture includes both the software- and hardware designs, and it must cover all customer requirements. In architecture design, developers specify what programming language is best for the individual task, the overall work and algorithm of the program, choice of different industry practices, and use of libraries or templates. For example, if the developer is using Raspberry Pi as a processing unit for application, Python language is a great choice. If Arduino is involved, developers will prefer C or Assembly language. Data structures depend on the application’s function. For example, if an online shopping app needs a cart management program, it will use the “list data” structure. But if this takes place on a browser, and the user must navigate from the current, next, or previous pages – the “Push-Pop” data structure will be used. For example, if you design a message application, there should be a button for contact selection, send a message, and a keyboard to type the message. The design will define the action of each of these buttons. The application platform is selected – this could be Android, Linux, Windows, iOS, etc. The communication channel for the application can communicate with other resources, such as the central server, or application of any other user. To keep the application and user’s data secure, different security measures are specified. For example, SSL traffic encryption secures the flow of information to and from the website. Password protection ensures applications can be safely used on a user’s device.
Coding / Software Development
During this step, software engineers write the actual program for the application’s required functionality. Based on project size, either a single developer or a team writes a program for the application. In the case of multiple developers, different tasks within an application are identified and each programmer is assigned one. Developing the tasks separately allows for more compatibility with programs of other tasks. Developers mainly know how the application works. So, they provide an outline for a user guide, product working, specifications, and troubleshooting process. This helps with the making of a complete user manual for the application. This may include answers to frequently asked questions. FAQs help the user understand application functions in a better way. During coding, developers encounter bugs and errors. These sometimes consume a lot of time as lengthy code usually makes mistakes hard to find. Different debugging tools are used to assist developers in finding glitches or errors. If the design is prepared in a detailed and organized manner the code development process is completed with less effort and sooner.
Testing / Quality Assurance
This is one of the critical stages in software development. Once the application is entirely developed, it is tested, and the performance of the application is evaluated. Errors and issues in the products are indicated, tracked, solved, and tested again. This is an iterative process where the application is tested repeatedly by Quality Assurance Engineers, until all issues are eradicated. Testing sometimes requires a specific environment. For example, sometimes a virtual environment is created to test the application, before deployment. Testing is done to ensure that each function of the application works properly. During the test phase, apart from the app’s functionality, its performance is also checked for lags in processing. This step reduces the chances of errors or glitches that the final users may encounter. As a result, higher user satisfaction is achieved, and more people are encouraged to use the application. In many SDLC models, testing is not a separate stage but the subset of all stages because testing is part of all stages. We encounter a lot of applications that either doesn’t work correctly, some of their functions don’t work as described, or there are glitches or bugs. These things happen with applications that are not appropriately tested after their development and release. Poorly tested applications create unsatisfied customers, who would quickly move to a different company and products.
Once the application is developed and tested, it is made available for public use. The deployment process can be simple, or complex based on the application itself. Some companies upload the application setup on their website and make it available for purchase and download. Such applications are easily installable. But sometimes, deployment can be a complicated process. For example, if you have developed a new application for a company and now you must upgrade their database. The database uses different systems that make the integration of upgrades a lengthy and challenging process. Sometimes, a product is not released entirely but in segments. First, a limited portion of the product is made available for users and evaluated in a real business environment. This is also referred to as ‘user acceptance testing’ (UAT). From this limited release, the company gets an idea of its market and usage. Moreover, getting feedback from the users for the released product helps the company to reevaluate the product specifications and improve them according to user demand. If the user accepts the initial release, then the final release is successful and will get users’ acceptance.
Operation and maintenance
Once the application is deployed and made available for use in the market, the development cycle is ended - or started over. Operation and maintenance experts are responsible for applications’ proper operation and handle user complaints related to bugs and problems. This phase is not only related to fixing errors, but it also includes upgrading the application requirements to meet the new market demands. This phase’s role is to keep the application up to date and enhance it to ensure that it attracts users and retains them. For example, an online store application with a lot of different payment methods; if a new payment method is introduced, it could end up the preferred choice by many. Hence, the application owner would like to add that method into the store’s application as well, provide, ease to the people using that service. Moreover, the user may demand the addition of new features that will be handled by the maintenance team. If the updating task is not very large, it will be handled within the maintenance and operation team. But if the new app version looks like a completely new project, a new SDLC model will be created and followed.
It is impractical to consider an environment where defined and organized processes are not required for software development. There are a lot of things that may go wrong in such settings and cause failure. It is essential to take help from the tested guidelines or rules, which can be used as a standard to get guidance for delivering the product successfully. It is always important to use prescribed methodologies for the software development process because they are predictable when viewed in a controlled environment. The software development methodology is a reusable process that can be repeated as many times as needed to reach the desired product capabilities and is closely related to performance indexes in Software Development. The following are some well-known methodologies being used by the majority of software developing companies.
This is considered one of the oldest and straightforward methodologies for the software development life cycle. This method offers a sequential and linear flow of steps. In this methodology, one step must be completed before moving onto the next one, since every following step depends on the outcomes or results of the previous one. Once a step is completed, there is no going back, as this model only allows forward direction through steps. In the waterfall methodology, each stage may have its plan to complete the requirement more effectively. One of the advantages of this methodology is its simplicity which allows us to follow and implement this model more easily. All activities to be carried out are well defined, which makes it easy to understand and follow. However, once a stage is completed, it is almost impossible to return to a previous state. The waterfall methodology is considered expensive and more time-consuming relative to other methods.
In this model, the product is separated into cycles enabling the developing process to deliver the working product in less time. Application versions are produced one after the other. Each version is tested to detect issues and find room for improvement. The information collected after testing a version is used to make changes and improvements in the previous design to achieve the required results. It is an iterative technique, and, in each iteration, a new small change is incremented from the previous iteration and tested to find the failures to improve the design in the next iteration. Each iteration is tied to a small goal, making the process fast and detecting the problems - easy. The main advantage of this model is its ability to provide high product quality in less time, developed by an iterative process of improvements for each product version. This model allows for the involvement of the customer. After each iteration, customer feedback on each successive version helps improve the product according to demand. It is one of the most flexible models since changes can be introduced at any process development stage. This model allows different teams to collaborate in the development and achieve a higher quality product. The agile model requires a team of specialized professionals focused on what each member must have as a skill set. If you do not define the scope of the project at the very start of it, this model might create challenges as changes in Agile are frequent. Since this model favors client feedback for changes, it sometimes leads the project in the wrong direction. The customer does not always have the best decisions and their elevated input in the project outcome is sometimes overemphasized.
Prototyping model is an approach of initially developing a working model of the required software product which have limited functionality and the most favorable features of the actual product. The client reports the issues and shortcomings in the functionality of the prototype to the developing company. These problems are fixed in the previous design and a new version of the prototype is developed, and, again, provided to the client for testing. Once the client is satisfied with the prototype, the full version of the product is developed. This model is usually used in larger projects with complex and large systems. Big projects require users to verify functionalities before approving the development of the final version. If software requirements are not evident to the client, or if the solution is not clear to the developers, this model helps find the most suitable solution without wasting much time. When users are involved in product development, the more accurate feedback of customers improves each version of the prototype. Errors and problems in functionality are identified and fixed at the very start of the development process. But if the client is not satisfied with the prototype, developers must provide a new one. This process goes on until a suitable solution is made. Revising a rejected design by the user makes this model more expensive, both in terms of time and money.
It is a risk-oriented model consisting of four main phases, including forming an objective, analyzing and resolving risks, developing and testing, and planning the next iteration. The software process follows these four phases iteratively. During the first phase, project requirements are gathered. Next, risks are evaluated, and alternative solutions are brought forth. Then, based on current information a prototype is developed and tested. This provides feedback for the project’s required changes and existing errors. Information from this stage is evaluated and used to plan the next iteration. The detailed risk analysis during the second phase reduces the chances of failures. Due to the cyclic nature of the Spiral Model, new functionality can be added at any stage of development.
While all these methodologies have their pros and cons, at the end of the day, it all boils down to client requirements, project specificity, and team size.
Some of these methodologies are older and becoming obsolete. However, there are still projects that, to this day, work only thanks to them. On the other hand, methodologies such as Agile always give project managers an upper hand and help them efficiently complete their projects.
If you want to learn more about CodeCoda’s Software Development Methodology, please continue reading here.