What is Software Development Life Cycle (SDLC)?

What is Software Development Life Cycle (SDLC)? Software development life cycle involves the phases to develop new software. It describes all the things which a client want for his new software. There are seven stages in this process. If you are looking for it. Then I might say you are in the right place. Because here I have provided you all about SDLC.

Software Development Life Cycle

Topics I will cover in this article are:

System Components

The system comprises of the following necessary components

  • Hardware
  • Software
  • People / Users
  • Data / Information
  • Communication setup

Our main discussion here is focused on the Application Software development process, leaving aside the software packages (which are always available in the market).

What is a System?

A system can define as a combination of some related components that interact with each to perform tasks.

What is Software Development Life Cycle (SDLC)?

To develop a system, various distinct phases are to be worked out. For this purpose, the SDLC (Software Development Life Cycle) was developed, which is an organized way to develop a successful System.

Software Development Life Cycle Phases
Software Development Life Cycle Phases

SDLC Phases:

  1. Preliminary Investigation or Early Investigation
  2. System Analysis
  3. Design
  4. Coding
  5. Testing
  6. Implementation
  7. Maintenance

1. Preliminary Investigation:

Preliminary Investigation Phase in SDLC
Preliminary Investigation Phase in SDLC

The objective of the preliminary investigation is to conduct an initial analysis and findings of the system as discussed below:

System Identification:

The system is to be identified at this stage of SDLC. This is a very important step as everything done in the future will depend on the basis of this definition.

System Scope:

The scope of the system is established at this stage of SDLC. Sometimes, it becomes necessary to delay the projects to certain limits due to financial. political, or time constraints.

Alternate solutions:

There may alternate solutions to develop the system. identify all those and choose the best one. The best strategy in this regard would be to interview the people inside the organization, clients or customers of the system suppliers and consultants. We can also
watch what the competitors are doing for the same type of systems.

Feasibility study:

We have to check out the financial, political, and time-frame viabilities to go ahead for the system. There may be some social and technical constraint to Considered also.

Preliminary plan:

Here, we need to wind up all the research and submit as a written document for approval. The readers of this document (also known as feasibility report) are top managers who will then decide about the future actions to be taken, based on this report. There might like to make a few amendments in the project or shelve it, depending on the whole early investigation.

2. Systems Analysis:

System Analysis Phase in SDLC
System Analysis Phase in SDLC

Here, the analyst will conduct the following activities:

Needs Analysis:

This activity is also called Requirements Analysis in SDLC. Here, the analyst would pu-together the requirements of the system from the users and the managers. The ‘developed system should satisfy the requirements during the testing phase of the software development life cycle.

Data Gathering:

For this activity. the systems analyst uses different tools methods. depending on the situation. They are discussed as under:

Written documents:

In case we want to computerize the existing manual system or upgrade the existing  system, much of the harmful information can be made available through these documents. They are reports, forms, memos, business plans, policy statements, organizational charts, and many Others.

Interviews:

Interviewing managers, users/clients, suppliers, and competitors will help the analysts/designers to gain more knowledge about the system. The emphasis is on the fact that the questions to asked from them should precise and relevant.

Questionnaires:

It may be difficult to interview many people, so it is better to make some questionnaires to collect the information from as many people as we like. This is a very convenient and inexpensive method to collect a handful of data sometimes the response may ambiguous and insufficient.

Observations:

The analyst or his team may go and watch working, behavior, and similar things to know more about the similar systems around. He may be a participant or non-participant observer depending on the permission he got from the other party.

Sampling:

If there were a large of People or events involved in the system, it would work on a portion of all of them to save time.

Data Analysis:

As we are living in the “Information age” so it is generally believed in today’s computing scenario that data or information is the precious commodity. Therefore, data must be accurate, complete, and available in the systems we design. So to keep it in proper shape, we have many tools available, For example, DFD (Data Flow Diagrams), System Flowcharts. Connectivity Diagrams, Grid Charts, and Decision Tables, etc.

Analysis report:

Once the analysis work is over, we need to document it in a presentable form to higher management for their review and approval of the project. This report should have three parts: First, it should explain how the current system (manual or automated if exists) works, Second, it should explain the problems in the existing system, finally, it should describe the requirements for the system and make recommendations for future.

3. Design:

Design Phase in SDLC
Design Phase in SDLC

In this phase of SDLC. the analyst works on preliminary (Logical) design. detail (Physical) design, and then writes a detailed report.

Logical design:

It describes the functional capabilities of a proposed system. It reviews the system requirements and considers the major system components. Case tools and project management software (MS-Project. Gantt chart. PERT chart etc) may be used to accomplish this task.

Physical design:

It describes how a proposed system will deliver general capabilities described in the Logical design. It will address the following points: Output requirements. input requirements. storage requirements, processing requirements, and system control and back up/recovery.

Report:

A detailed report on logical, physical design is to submit to the higher management along with some sort of presentation, explaining them the details of the proposed system.

4. Coding:

Coding Phase in SDLC
Coding Phase in SDLC

This is the core area of the system development process in software development life cycle. It consists of writing the segments and programs, which will be coupled together in the shape Of a complete system. It needs a lot of time, effort and budget to acquire a workable system.

The program specifications, algorithms, flowcharts are given to the programmers/ software engineers to code the required programs. Off-the-Shelf-Components (already •written programs) can also be used and in the system to save time and effort.

5. Testing:

Testing Phase
Testing Phase in SDLC

Having proper hardware acquired, programs can be tested in two stages.

Unit-testing:

It is also called modular testing where individual modules, programs can be tested using a test (sample) data.

System-testing:

In this, parts Or modules are linked together to test their workability as a one system Actual data may be used to do the system testing and at the same time, erroneous data can also be used to check the weather system fails or not.

If the system passes all the tests, We can implement the system on the Servers. so that the organization and other clients can use it.

6. Implementation:

Implementation Phase
Implementation Phase in SDLC

This activity consists of transferring the hardware, software, and data (files, database, etc) to the new working environment (server). Users Of the system are also trained in this phase. An implementation may be achieved in five approaches.

Direct Implementation:

In this way, the users Start using the new system right away and Stop working on the Old one.

Parallel Implementation:

Using this approach. tip new and old are used side by side until it is felt that the system is quite reliable.

Phased Implementation:

In this approach, parts of the system are implemented from time to time, until the whole system is implemented,

Pilot Implementation:

This type of implementation allows us to implement the complete system but to a selected group of users or selected departments.

User Training:

Involving users in the SDLC process from the beginning and ensuring their proper training is very much essential throughout the system design activity. A variety of methods/tools are used to do so i.e. Instruction Manual, Videotapes/CDs. and Lectures etc. The training may be conducted “In-house” or it may “Contracted out”.

Comment:

In general, the pilot and phased implementations are the favored and popular approaches to implement the systems. The phased approach is preferable for communications where different types of functions are carried whereas Pilot is preferred, where almost the same type of work is going on in the organization.

7. Maintenance:

Maintenance Phase
Maintenance Phase in SDLC

The last phase adjusts and improves the system by considering the user’s evaluation. Feedback, and enhancements based on their due recommendations. In this phase. due maintenance and help are also to the against queries, problems, and ambiguities.

SDLC Models:

SDLC models
SDLC models

There are several software development life cycle models. These methods describe the methodology to build software from start to finish. These are all called as the SDLC methodologies. These are given Below.

  • Waterfall
  • Iterative
  • V models
  • Spiral
  • Lean
  • Agile
  • Prototype
  • DevOps

Waterfall:

The waterfall approach is one of the oldest SDL models. But has been benefited in recent years. This model includes a stringent structure that will set the needs of all systems at a very beginning. Design and development steps can only begin at this time.

After the development is completed, the product is tested against the initial needs and the assignment is assigned again. Companies in the software industry generally require more eligibility to offer a waterfall method, but it is still a strong solution to some specific projects, especially government contractors.

Iterative:

The iterative procedure takes the cascade model and goes through it a few times in little augmentations. As opposed to extending the whole task over the periods of the SDLC, each progression is transformed into a few smaller than expected ventures that can include an incentive as the item develops.

The iterative methodology shares a considerable lot of indistinguishable objectives from the spry model, aside from outside clients are less included and the extent of every augmentation is regularly fixed.

DevOps:

DevOps is one of the most current SDLC systems and is being received by numerous product organizations and IT associations. As its name recommends, the reason of DevOps is to unite advancement groups with operational groups so as to streamline conveyance and backing.

The benefits of such a methodology are, that changes become increasingly liquid, while the authoritative hazard is diminished. Groups must have adaptable assets all together for a DevOps course of action to succeed.

V-Model:

Advancement of the great cascade system, the v-model SDLC procedure steps are flipped upwards after the coding stage. The v-model has a severe methodology, with the following stage starting just when the last stage is finished.

This absence of adaptability and higher-chance strategy isn’t prescribed for little undertakings, however, the v-model is simpler to oversee and control. For undertakings where necessities are static and plainly expressed, and where early testing is wanted, this methodology can be a decent decision.

Spiral:

The spiral procedure enables groups to receive various SDLC models dependent on the hazard examples of the given undertaking. A mix of the iterative and cascade approaches, the test with the winding model is realizing when is the correct minute to move onto the following stage.

The business that isn’t sure about their necessities or expects major alters during their mid to high-hazard venture can profit by the versatility of this philosophy.

Lean:

The agile and lean methodologies are firmly interconnected, as the two of them center around conveyance speed and consistent improvement. Interestingly, the lean model is established in assembling best practices where overabundance waste and exertion are viewed as the biggest hazard to an association.

With regards to programming and activities, the lean SDLC system centers around diminishing waste in each stage, including booking, cost, and degree. This methodology is most convincing for associations with severe equipment prerequisites and other obtainment needs.

Agile:

The agile strategy is something contrary to the waterfall approach. As opposed to treating prerequisites, plan, and testing as huge successive advances, a light-footed model makes them every progressing procedure that requires association from engineers, the board, and clients.

Work is commonly broken into 2-multi-week portions known as “runs,” in which the dependable groups handle the real needs of their clients and perform testing as they go. Lithe will in general function admirably in little associations, particularly new businesses, where speed and adaptability are fundamental.

Prototype:

In the prototype methodology, the plan group’s center is to deliver an early model of the new framework, programming, or application. This model won’t have full usefulness or be completely tried, yet it will give outside clients a feeling of what’s to come. At that point, the input can be assembled and executed all through the remainder of the SDLC stages.

The prototyping approach functions admirably for organizations in developing enterprises or new innovations.

Software Development Life Cycle Phases and Models

SDLC Phases and Models

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Conclusion:

So, this was all about the “software development life cycle” (SDLC). If you have any query, feedback or suggestion, then feel free to comment below. If you really liked this article, then don’t forget to appreciate our effort by sharing this article with your loving ones.

Software Development life cycle is the actual method to create the software from start to end. You need to follow all the stages of SDLC to build professional software for yourselves, or for your clients.

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2 thoughts on “What is Software Development Life Cycle (SDLC)?”

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