The Ultimate Guide to Understanding and Using a System Development Life Cycle

By Kate Eby | June 27, 2017

There is a lot of literature on specific systems development life cycle (SDLC) methodologies, tools, and applications for successful system deployment. Not just limited to purely technical activities, SDLC involves process and procedure development, change management, identifying user experiences, policy/procedure development, user impact, and proper security procedures. Books such as David Avison and Guy Fitzgerald’s Information Systems Development and Alan Daniels and Don Yeates’ Basic Systems Analysis, delve into the intricacies of information systems development lifecycles. 
This article will provide an in-depth analysis of the history, definition, phases, benefits, and disadvantages, along with solutions that support the system development life cycle.

What Is a System Development Life Cycle?

In order to understand the concept of system development life cycle, we must first define a system. A system is any information technology component - hardware, software, or a combination of the two. Each system goes through a development life cycle from initial planning through to disposition. Some methodologies provide the necessary framework to guide the challenging and complex process with an aim to avoid costly mistakes and expedite development, all of which have the same goal of moving physical or software-based systems through phases.

A system development life cycle is similar to a project life cycle. In fact, in many cases, SDLC is considered a phased project model that defines the organizational, personnel, policy, and budgeting constraints of a large scale systems project. The term “project” implies that there is a beginning and an end to the cycle and the methods inherent in a systems development life cycle strategy provide clear, distinct, and defined phases of work in the elements of planning, designing, testing, deploying, and maintaining information systems.

Those involved in the SDLC include the c-suite executives, but it is the project/program managers, software and systems engineers, users, and the development team who handle the multi-layered process. Each project has its own level of complexity in planning and execution, and often within an organization, project managers employ numerous SDLC methods. Even when an enterprise utilizes the same methods, different project tools and techniques can differ dramatically.

History and Origin of the System Development Lifecycle

Completely defined in 1971, the term originated in the 1960s when mainframe computers filled entire rooms and a pressing need developed to define processes and equipment centered on building large business systems. In those days, teams were small, centralized, and users were ‘less’ demanding. This type of scenario meant that there was not a true need for refined methodologies to drive the life cycle of system development. However, technology has evolved, systems have become increasingly complex, and users have become accustomed to well-functioning technology. Models and frameworks have been developed to guide companies through an organized system development life cycle. Today, the traditional approaches to technology system development have been adjusted to meet the ever-changing, complex needs of each unique organization and their users. Below you will find sequential steps to SDLC, but each company will vary in their process.

The Phases of SDLC

The SDLC framework provides a step-by-step guide through the phases of implementing both a physical and software based system. A variety of models are available, but whether utilizing the oldest method of SDLC, the waterfall method, adopting an Agile method, or employing a hybrid of several methods, all methods embrace a phased iterative structure that you can adapt to your organization’s needs. 
You may find phases with varying naming conventions, but these are the most common stages of SDLC. Organizations may adopt any, all, or a variation of these phases:

  • Analysis/Feasibility: For an SDLC strategy to work there should be a strong idea of what deficiencies exist in the current structure and the goals for the new approach. A feasibility study determines if you can or should accomplish the goals of the plan. Information is gathered and analyzed to identify what technical assets, personnel, and training is already in place and utilized. The study also inventories what is needed to augment or replace, and at what cost. During this phase you determine the overall project scope, including economic, operational and human factors, identify key personnel, and develop timelines. 
  • Planning/Requirements: A plan can include adapting a current system to meet new needs or developing a completely new system. This phase defines user requirements, identifies needed features, functions, and customizations, and investigates overall capabilities
  • Design: Once you make the plan and identify costs, systems, and user requirements, a detailed system design can begin that includes features and other documentation. The architects can then build a sample framework.
  • System Development: An approved design is the catalyst for authorizing development for the new or augmented system. Some say that this is the most robust part of the life cycle. During this phase, developers write code and you construct and fine-tune technical and physical configurations. 
  • Testing: Users are brought in to test before deployment to identify areas of concern or improvement.
  • Deployment: The system is put into a production environment and used to conduct business.
  • Maintenance: The cyclical nature of SDLC recognizes that the process of change and upgrading are constant. Carry out the replacement of outdated hardware/software, security upgrades, and continuous improvement on a regular basis. 
  • Evaluation:  An often overlooked element of any large scale system roll-out is the evaluation process, which supports the continuous improvement of the system. The team continuously reviews what is working and what is in need of improvement. This can mean recommending additional training, procedures, or upgrades.
  • Disposition/Disposal/End-of-Life: A well-rounded life cycle identifies and decommissions surplus or obsolete assets at the end of their life cycle. Included in this phase is the secure retrieval of data and information for preservation, as well as, the physical disposition of an asset.

Following each phase of a system development life cycle the team and project manager may establish a baseline or milestones in the process. The baseline may include start date, end date, phase/stage duration, and budget data. These baseline assists the project manager in monitoring performance.


System Development Lifecycle

There is an increased interest in system security at all levels of the life cycle, that include the elements of confidentiality, information availability, the integrity of the information, overall system protection, and risk mitigation. Aligning the development team and the security team is a best practice that ensures security measures are built into the various phases of the system development life cycle. For example, SAMM, the Software Assurance Maturity Model is a framework that aids organizations in evaluating their software security practices, building security programs, demonstrating security improvements, and measuring security-related activities. In addition, governance and regulations have found their way into technology, and stringent requirements for data integrity impact the team developing technology systems. Regulations impact organizations differently, but the most common are Sarbanes-Oxley, COBIT, and HIPAA.

Each company will have their own defined best practices for the various stages of development. For example, testing may involve a defined number of end users and use case scenarios in order to be deemed successful, and maintenance may include quarterly, mandatory system upgrades.

Benefits of a Well-Defined System Development Life Cycle

There are numerous benefits for deploying a system development life cycle that include the ability to pre-plan and analyze structured phases and goals. The goal-oriented processes of SDLC are not limited to a one-size-fits-all methodology and can be adapted to meet changing needs. However, if well-defined for your business, you can:

  • Have a clear view of the entire project, the personnel involved, staffing requirements, a defined timeline, and precise objectives to close each phase.  
  • Base costs and staffing decisions on concrete information and need.  
  • Provide verification, goals, and deliverables that meet design and development standards for each step of the project, developing extensive documentation throughout. 
  • Provide developers a measure of control through the iterative, phased approach, which usually begins with an analysis of costs and timelines.  
  • Improve the quality of the final system with verification at each phase.

Disadvantages of a Structured System Development Life Cycle

In these same areas, there are some who find disadvantages when following a structured SDLC. Some of the downfalls include:

  • Many of the methods are considered inflexible, and some suffer from outdated processes. 
  • Since you base the plan on requirements and assumptions made well ahead of the project’s deployment, many practitioners identify difficulty in responding to changing circumstances in the life cycle. 
  • Some consider the structured nature of SDLC to be time and cost prohibitive.
  • Some teams find it too complex to estimate costs, are unable to define details early on in the project, and do not like rigidly defined requirements.
  • Testing at the end of the life cycle is not favorable to all development teams. Many prefer to test throughout their process.
  • The documentation involved in a structured SDLC approach can be overwhelming.
  • Teams who prefer to move between stages quickly and even move back to a previous phase find the structured phase approach challenging.

Another Form of SDLC: The Software Development Life Cycle

When the word “systems” is replaced with the word “software,” it creates another version of SDLC. The Software Development Life Cycle follows an international standard known as ISO 12207 2008. In this standard, phasing similar to the traditional systems development life cycle is outlined to include the acquisition of software, development of new software, operations, maintenance, and disposal of software products. An identified area of growing concern and increased adoption continues to revolve around the need for enhanced security functionality and data protection.
Like systems development life cycle, discussed previously, there are numerous methods and frameworks that you can adopt for software development including:

  • The Waterfall Method is a steady sequence of activity that flows in a downward direction much like its name. This traditional engineering process that closes each phase upon completion is often criticized for being too rigid.
  • The V-Shaped Model is an adaptation of Waterfall that has testing as an integral part to close each phase.
  • The Prototype Method advocates a plan to build numerous software methods that allow different elements to be “tried-out” before fully developing them. The Prototype method can increase “buy-in” by users/customers. 
  • Rapid Application Development (RAD) is a hybrid of the prototype method, but works to de-emphasize initial planning to rapidly prototype and test potential solutions.
  • The Spiral Method provides more process steps, which are graphically viewed in a spiral formation and is generally credited to provide greater flexibility and process adaptation.
  • Agile Methods are software-based systems that provide feedback through an iterative process and include Kanban, Scrum, Extreme Programming (XP), and Dynamic systems development method (DSDM).

Other models and methods include Synchronize and Stabilize, Dynamic Systems Development (DSDM), Big Bang Model, Fountain, and Evolutionary Prototyping Model, among others. Each has elements of a defined stepped process with variations to adapt for flexibility.
Choosing the right SDLC method is critical for the success of your development project as well as for your business. There is not a hard and fast rule that you must choose only a single methodology for each project, but if you are to invest in a methodology and supporting tools, it is wise to utilize them as much as possible. To choose the right methodology you must first:

  • Understand the various methodologies, their advantages, and disadvantages.
  • Become familiar with the team dynamics, stakeholders involved, and the projects you will be managing.
  • Compare the methodologies to the criteria your team has defined and business facts – size of your team, type of technology projects, complexity of projects, etc. The methodology should be easy for the team to understand and learn. 
  • Share the decision and reasoning with your team and stakeholders.

Project Managing the System Development Life Cycle

The iterative and phased stages of an SDLC benefit from the leadership of a dedicated project manager. The major goal of an SDLC is to provide cost effective and appropriate enhancements or changes to the information system that meet overall corporate goals. The project manager is responsible for executing and closing all the linear steps of planning, building, and maintaining the new or improved system throughout the process. 

Other elements for the project manager involve administration of human elements including communication, change management strategies, and training, initiating and driving the planning for the project, setting and monitoring goals, providing avenues for communication and training, and keeping track of budgets and timelines. The project manager is the overall control agent for a strong SDLC process.


Software Solutions That Support the System Development Life Cycle

SDLC products from software vendors promise organizational clarity, modern process development procedures, legacy application strategies, and improved security features. Many options provide customized or integrated solutions. Vendors such as Oracle, Airbrake, and Veracode provide software development solutions in their complete enterprise software offerings. Many of these vendors also have a strong focus on identifying and de-bugging systems that may support the process of testing in software development life cycles. In many cases, SDLC teams utilize a variety of software solutions to support the varying stages. For example, requirements may be gathered, tracked and managed in one solution while testing use cases may take place in a completely different solution. 

Regardless of the process implemented and the tools used, all require the crucial element of documentation to support findings, close iterative phases, and to analyze success. Today’s increasing demand for data and information security also factor into the overall planning, training, testing, and deployment of a system. However, one of the most important elements of success of any SDLC method continues to be in the initial planning, followed by choosing the appropriate framework and method, and finally sticking to, deploying, and maintaining a robust project plan.

Start Managing Your System Development Life Cycle with a Helpful Template

Project managers in charge of SDLC need the right tools to help manage the entire process, provide visibility to key stakeholders, and create a central repository for documentation created during each phase. One such tool is Smartsheet, a work management and automation platform that enables enterprises and teams to work better. 

With its customizable spreadsheet interface and powerful collaboration features, Smartsheet allows for streamlined project and process management. Use Smartsheet’s SDLC with Gantt template to get started quickly, and help manage the planning, development, testing, and deployment stages of system development. Create a timeline with milestones and dependencies to track progress, and set up automated alerts to notify you as anything changes. Share your plan with your team and key stakeholders to provide visibility, and assign tasks to individuals to ensure nothing slips through the cracks.

Try the Smartsheet SDLC template for free, today.

Create Your SDLC Plan in Smartsheet


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When teams have clarity into the work getting done, there’s no telling how much more they can accomplish in the same amount of time. Try Smartsheet for free, today.




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