SDLC

Software Development Life Cycle Models and Methodologies

Introduction

Software development life cycle (SDLC) is a series of phases that provide a common understanding of the software building process. How the software will be realized and developed from the business understanding and requirements elicitation phase to convert these business ideas and requirements into functions and features until its usage and operation to achieve the business needs. A good software engineer should have enough knowledge on how to choose the SDLC model based on the project context and the business requirements.

Therefore, it may be required to choose the right SDLC model according to the specific concerns and requirements of the project to ensure its success. I wrote another article on how to choose the right SDLC, you can follow this link for more information. Moreover, to learn more about Software Testing life cycles and SDLC phases you follow the links highlighted here.

In this article, we will explore the different types of SDLC models and the advantages and disadvantages of each one, and when to use them.

You can think of SDLC models as tools that you can use to better deliver your software project. Therefore, knowing and understanding each model and when to use it, the advantages and disadvantages of each one are important to know which one is suitable for the project context.

tools
Tools

Types of Software developing life cycles (SDLC)

Waterfall Model

Description

The Waterfall Model is a linear sequential flow. In which progress is seen as flowing steadily downwards (like a waterfall) through the phases of software implementation. This means that any phase in the development process begins only if the previous phase is complete. The waterfall approach does not define the process to go back to the previous phase to handle changes in requirement. The waterfall approach is the earliest approach and most widely known that was used for software development.

Waterfall Model
Waterfall Model

The usage

For projects which not focus on changing the requirements, for example, projects initiated from a request for proposals (RFPs), the customer has very clear documented requirements

Advantages and Disadvantages

AdvantagesDisadvantages
  • Easy to explain to the users.
  • Structures approach.
  • Stages and activities are well defined.
  • Helps to plan and schedule the project.
  • Verification at each stage ensures early detection of errors/misunderstandings.
  • Each phase has specific deliverables.
  • Assumes that the requirements of a system can be frozen.
  • Very difficult to go back to any stage after it is finished.

  • A little flexibility and adjusting the scope are difficult and expensive.
  • Costly and required more time, in addition to the detailed plan.
Advantages/Disadvantages table

V-Shaped Model

Description

It is an extension of the waterfall model, Instead of moving down in a linear way, the process steps are bent upwards after the implementation and coding phase, to form the typical V shape. The major difference between the V-shaped model and the waterfall model is the early test planning in the V-shaped model.

V-Shaped
V-Shaped Model

The usage

  • Software requirements clearly defined and known
  • Software development technologies and tools are well-known

Advantages and Disadvantages

AdvantagesDisadvantages
  • Simple and easy to use
  • Each phase has specific deliverables.
  • Higher chance of success over the waterfall model due to the development of test plans early on during the life cycle.
  • Works well for where requirements are easily understood.
  • Verification and validation of the product in the early stages of product development.
  • Very inflexible, like the waterfall model.
  • Adjusting the scope is difficult and expensive. The software is developed during the implementation phase, so no early prototypes of the software are produced. The model doesn’t provide a clear path for problems found during the testing phases.
  • Costly and required more time, in addition to a detailed plan
Advantages/Disadvantages table

Prototyping Model

Description

It refers to the activity of creating prototypes of software applications, for example, incomplete versions of the software program being developed. It is an activity that can occur in software development and It used to visualize some components of the software to limit the gap of misunderstanding the customer requirements by the development team. This also will reduce the iterations that may occur in the waterfall approach and are hard to be implemented due to the inflexibility of the waterfall approach. So, when the final prototype is developed, the requirement is considered to be frozen.

It has some types, such as:

  • Throwaway prototyping: Prototypes that are eventually discarded rather than becoming a part of the finally delivered software
Throwaway prototyping
Throwaway prototyping
  • Evolutionary prototyping: prototypes that evolve into the final system through an iterative incorporation of user feedback.
Evolutionary prototyping
Evolutionary prototyping
  • Incremental prototyping: The final product is built as separate prototypes. In the end, the separate prototypes are merged in an overall design.
Incremental Model
Incremental prototyping
  • Extreme prototyping: used in web applications mainly. Basically, it breaks down web development into three phases, each one based on the preceding one. The first phase is a static prototype that consists mainly of HTML pages. In the second phase, the screens are programmed and fully functional using a simulated services layer. In the third phase, the services are implemented

The usage

  • This process can be used with any software developing life cycle model. While this shall be chosen when you are developing a system has user interactions. So, if the system does not have user interactions, such as a system does some calculations shall not have prototypes.

Advantages and Disadvantages

AdvantagesDisadvantages
  • Reduced time and costs, but this can be a disadvantage if the developer loses time in developing the prototypes.
  • Improved and increased user involvement.
  • Insufficient analysis. User confusion of prototype and finished system.
  • Developer misunderstanding of user objectives.
  • Excessive development time of the prototype.
  • It is costly to implement the prototypes
Advantages/Disadvantages table

Spiral Model (SDM)

Description

It is combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. This model of development combines the features of the prototyping model and the waterfall model. The spiral model is favored for large, expensive, and complicated projects. This model uses many of the same phases as the waterfall model, in essentially the same order, separated by planning, risk assessment, and the building of prototypes and simulations.

spiral model
Spiral Model

The usage

It is used in large applications and systems which built-in small phases or segments.

Advantages and Disadvantages

AdvantagesDisadvantages
  • Estimates (i.e. budget, schedule, etc.) become more realistic as work progressed because important issues are discovered earlier.
  • Early involvement of developers.
  • Manages risks and develops the system into phases.
  • High cost and time to reach the final product.
  • Needs special skills to evaluate the risks and assumptions.
  • Highly customized limiting re-usability
Advantages/Disadvantages table

Iterative and Incremental Model

Description

It is developed to overcome the weaknesses of the waterfall model. It starts with initial planning and ends with deployment with the cyclic interactions in between. The basic idea behind this method is to develop a system through repeated cycles (iterative) and in smaller portions at a time (incremental), allowing software developers to take advantage of what was learned during the development of earlier parts or versions of the system. It can consist of mini waterfalls or mini V-Shaped models.

incremental-sdlc

The usage

It is used in shrink-wrap applications and large systems which built-in small phases or segments. Also, can be used in a system that has separated components, for example, an ERP system. Which we can start with the budget module as a first iteration and then we can start with the inventory module and so forth.

Mini V-Model
Iterative and Incremental Model

Advantages and Disadvantages

AdvantagesDisadvantages
  • Produces business value early in the development lifecycle.
  • Better use of scarce resources through proper increment definition.
  • Can accommodate some change requests between increments.
  • More focused on customer value than the linear approaches.
  • We can detect project issues and changes earlier.
  • Requires heavy documentation.
  • Follows a defined set of processes.
  • Defines increments based on function and feature dependencies.
  • Requires more customer involvement than the linear approaches.
  • Partitioning the functions and features might be problematic.
  • Integration between the iterations can be an issue if it is not considered during the development and project planning.
Advantages/Disadvantages table

Agile Model

Description

It is based on iterative and incremental development, where requirements and solutions evolve through collaboration between cross-functional teams.

agile-SDLC
Scrum Agile Model

The usage

It can be used with any type of project, but it needs more engagement from the customer and to be interactive. Also, we can use it when the customer needs to have some functional requirements ready in less than three weeks and the requirements are not clear enough. This will enable more valuable and workable pieces for software early which also increases customer satisfaction.

Advantages and Disadvantages

AdvantagesDisadvantages
  • Decrease the time required to avail some system features.
  • Face-to-face communication and continuous inputs from customer representatives leave no space for guesswork. The end result is high-quality software in the least possible time duration and satisfied customers
  • Scalability.
  • The ability and collaboration of the customer to express user needs.
  • Documentation is done at later stages.
  • Reduce the usability of components.
  • Needs special skills for the team.
Advantages/Disadvantages table

Here is a consolidated presentation to illustrate most of the popular software development models.

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Software Development Life Cycle Models and Methodologies
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Software Development Life Cycle Models and Methodologies
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Software development life cycle (SDLC) is a series of phases that provide a common understanding of the software building process.
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395 responses to “Software Development Life Cycle Models and Methodologies”

  1. Ramya Avatar
    Ramya

    Good Post

  2. p6 Avatar
    p6

    For large Construction projects with huge budget; it becomes very difficult for the project team to handle the tasks So, it becomes very necessary to provide a tool in the hand of project team that helps keep a track of activities in the project.

  3. CodeWraps Avatar
    CodeWraps

    Hello, I Liked your blog so informative idea to share with us! Thank you so much for sharing this blog. This is a great post on the Software Development and much more . Thanks once again and best of luck.

    1. Mohamed Sami Avatar

      Thank you

  4. RAJA Avatar
    RAJA

    very informative
    THANKS

  5. Nency Kundra Avatar
    Nency Kundra

    I think the software development life cycle (SDLC) refers to the process followed by software developers to develop high-quality software products and provides a framework that outlines the tasks that need to be performed in each phase of software development.Thanks for sharing this useful article.

  6. Manufacturing ERP Avatar
    Manufacturing ERP

    The illustration is too good to grasp the concepts. Keep doing the great work!

  7. jhanvi mehta Avatar
    jhanvi mehta

    Thanks a lot for sharing this blog. Really nice and fresh content. All the information is helpful for us. Keep giving us more information.

  8. rajitha987 Avatar
    rajitha987

    Thank you for sharing this informative article about software-development-life-cycle-models.

  9. vamshidhar Avatar
    vamshidhar

    Thank you for sharing the article of software development of life cycle models.

  10. […] 11. nädala ülesandeks oli analüüsida ühte tarkvara arendus- ja ühte ärimudelit. Scrum meetod on agiilne tarkvaraarenduse mudel, mis aitab inimestel ja organisatsioonidel koostöö abil suurte projektidega lihtsamini hakkama saada, selle mõte on üpris lihtne. Põhiliselt jagatakse terve töö osadeks, mida see meetod kutsub sprintideks. Sprint on kindel ajalimiit, mis kestab tavaliselt umbes 1 kuu või vähem ja peab lõpuks saavutama ettemääratud eesmärgi. Iga päev toimuvad sprindi jooksul scrum koosolekud, et arutleda eelmisest koosolekust saati tehtud tööd, eesmärke selleks päevaks ja tulevikuks ning probleeme, kui neid on tekkinud. Firma, kes nii töötab on näiteks Bandai Namco Studios. Meeskonnas, kus seda meetodit kasutatakse on tavaliselt kuni 10 liiget ja kõigil on enda roll. Arendusmeeskond, kes tegelevad terve arendusprotsessiga, toote omanik, kes suunab ja juhib meeskonnatööd ning “Scrum Master”, kes suhtleb nii meeskonna, kui ka kilendiga ning jälgib, et scrum protsess töötaks õigesti. Scrum meetodi effektiivsus tuleb suures osas sellest, et kõik liikmed on üksteisega väga avatud enda töö suhtes. Kuna koosolekud toimuvad nii tihti kaastöötajatega tekib kõigil rohkem kohusetunnet püsida ajakavas ja kui probleemid tekivad, on võimalus sellest kohe teada anda.Tarkvararent (application service providing, ASP) ärimudel tähendab täpselt seda, mida nimi ütleb. Paljudel teenused tänapäeval kasutavad maksemeetodit, kus tarbija peab kas iga kuu või aasta maksma, et ta saaks jätkata teenuse kasutamist. Näiteks NordVPN (teenus mis pakub ostjale internetiprivaatsust) lubab valida kas 1 kuu- 1 aasta- või 2 aasta pikkuse plaani. See tähendab, et maksmine toimub ikkagi iga kuu, aga neil toimuvad tihti allahindlused ja mida pikema plaani ostja valib, seda rohkem raha ta kulutab kokku, aga iga kuu makse on odavam, kas siis 1 või 2 aasta jaoks olenevalt valikust.ASP muutub aina populaarsemaks, sest see annab tootjatele ühekordsete ostude asemel iga kuu sissetulekut ja aja jooksul saab neile teenida palju rohkem raha.Viited:https://en.wikipedia.org/wiki/Scrum_(software_development)https://melsatar.blog/2012/03/15/software-development-life-cycle-models-and-methodologies/https://scrumguides.org/scrum-guide.htmlhttps://www.youtube.com/watch?v=e_TxH59MclAhttps://nordvpn.com/ […]

  11. […] I found that there are lots of similarities in objectives, concerns, and challenges with the software engineering development process. This beauty of knowing the similarities and differences can make us learn how we can use the […]

  12. shaker Avatar
    shaker

    which model is effective for creating a transportation system

    1. Mohamed Sami Avatar

      Hi Shaker, there are many criteria to decide what would be the suitable one. Please check how to select the SDLC article to guide you based on the input you have.

  13. autodesk Avatar
    autodesk

    By now, it is evident that 4D BIM (construction sequencing) can be the catalyst for an essential change in the way we design, manage and develop construction projects.

  14. Admin Avatar
    Admin

    thanks for share excellent article on Software Development Life Cycle Models and Methodologies .

    1. Mohamed Sami Avatar

      Thank you so much

  15. CharterGlobal2021 Avatar

    Thanks for sharing the article. It’s looking good. My point of view, When faced with the task of producing high-quality software that meets a client’s expectations, requirements, time-frame, and cost estimations; understanding the SDLC is crucial. So, It is used to create complex applications of varying sizes and scales, such as Agile, Waterfall, and Spiral. Each model follows a particular life cycle in order to ensure success in the process of software development.

  16. Abhishek Jajoo Avatar

    which life cycle model would you follow for developing software for each of the following applications? Mention the reasons behind your choice of a particular life cycle model. i) A well-understood data processing application. ii) A new software that would connect computers through satellite communication. Assume that your team has no previous experience in developing satellite communication software. iii) A software that would function as the controller of a telephone switching system. 08 iv) A new library automation software that would link various libraries in the city. v) An extremely large software that would provide, monitor, and control cellular communication among its subscribers using a set of revolving satellites. vi) A new text editor. vii) A compiler for a new language. viii) The graphical user interface part of a large software

  17. ian Avatar
    ian

    For example, one of the software development team leaves on the middle of the project, how the underlying principles of SDLC can help to easily hire or pick a new member to continue his/her work?

  18. webol Avatar

    This article is so innovative and well constructed I got lot of information from this post. Keep writing related to the topics on your site.

    1. Mohamed Sami Avatar

      Thank you 🙏

  19. Usama Rashid Avatar
    Usama Rashid

    Write the detailed software development approach that you would adopt in the context of scenario given:
    A hospital named XYZ requires a laboratory management system and has contacted your firm. You have 20 programmers, out of which 15 are busy with other projects for the time being. The hospital intends to acquire laboratory equipment, which they want to interface with the computer system. The annual evaluation of the hospital is due soon, in which computerization initiatives are appreciated
    Please guide me.

  20. Nami L. Avatar
    Nami L.

    Hi, just wanna ask if you have been a member of software development. What software paradigm or model you used and why did you use it? I just need it for academic purposes, I need to find/ask someone who is/was a member of software development. Thank you.

    1. Mohamed Sami Avatar

      Do you have a questionnaire form that you would like to fill?

Let me know your thoughts

Mohamed Sami

About the author

Mohamed Sami is a Industry Advisor who has a solid engineering background, he has more than 18 years of professional experience and he was involved in more than 40 government national projects with holding different roles and responsibilities, from national projects execution and management to drafting of the conceptual architecture and solutions design. Furthermore, Mohamed contributed to various digital strategies in the government sector, which improved his business and technical skills over his career development.

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