SDLC is an exceptionally large and comprehensive process that includes a great deal of testing and development activities, methods, methodologies, and tools, amongst others. It entails meticulous outlining in addition to administration, computation, and organization. The creation of useful applications or software is directly proportional to the culmination of each and every effort put forth by software engineers. The iterative model is also a part of the software development life cycle (SDLC).
A particular iteration of a sdlc that focuses on fundamental, uncomplicated execution, which then gradually profits from higher complexity and wider characteristics, setting to the ultimate system, has been brought to a successful conclusion. In a nutshell, development according to the iterative model is a strategy for breaking the process of developing software for a massive application into a number of smaller, more manageable parts. The iterative model’s life cycle model did not start out with all of the stipulations at the beginning. Specifically with regard to the model, the development of the software begins with designating and running the one and only component of the software that will be analyzed in order to recognize later specifications. In addition, the iterative model has a process that starts with the straightforward execution of a small collection of the software requirements. From there, the process iteratively improves the developing variants until the entire system is executed and ready to be redistributed. Iterative model releases are developed over the course of a specific and predetermined period of time that is referred to as an iteration.
In addition to that, the iteration focuses on a particular collection of requirements. Every cycle culminates in the production of a system that can be put to use, such as a particular iteration’s results in a release that can be put into action. The iterative model makes it possible to obtain earlier stages, which are then modified in accordance with their respective statuses. When the software development life cycle, also known as the SDLC, has reached its conclusion, the product’s final result is brought back into view. Typically, development using the iterative model is used in conjunction with accumulative development, which is a process in which a lengthy cycle of software development is divided into shorter sections that build upon one another. These sections build upon one another as the cycle progresses.
As a result, the iterative model will be applied to the subsequent outlines, which are as follows:
- It is possible to ascertain and comprehend the system’s requirements in their entirety.
- Significant specifications are determined, while the procedure of the development process reveals only a few functionalities and areas where improvements are required.
- The development team is tasked with acquiring the most up-to-date technology at all times and making use of that technology while the project is in progress.
- Things like this could change in the future, provided that there aren’t many purposes or characteristics that pose a particularly high risk. The resources with the necessary skills that are not easily accessible and are arranged to be used based on a contract for specific iterations.
The development process of the iterative model follows a circular pattern, in contrast to the approach taken by conventional models, which emphasises being careful and methodical at each stage of the process. In this entire process, only the preliminary planning has been completed. After that, fewer stages are repeated repeatedly, with the complexity of each cycle gradually increasing and software iteration taking place.
Origination and Implementations
The iterative method were used in projects in 1950s, despite the fact that agile development models like the iterative model have come to be widely regarded as an improvement over the waterfall model of the past. While iterative development models used in agile development have evolved from the conventional waterfall model of the past to become widely recognised. The US Air Force and NASA worked together during this time to build the hypersonic X-15 aircraft, using an iterative design method for the majority of the project. Even though Project Mercury, the first manned space flight for the United States of America, wasn’t a software development project per se, NASA decided to use an iterative model because of the process’s success.
In the subsequent decades that have passed since then, iterative methods have been implemented in a wide variety of software applications. These applications range from contemporary web applications and high-performance gaming clients all the way up to the software acquisition standard document 5000.2 for the United States Department of Defense, which states that “There are two ways to reach full capability: the evolutionary method and the single-step (or waterfall) method. It is recommended to take an evolutionary approach.”
Features of the Iterative Model
- The iterative model involves the creation of an initial base software by making use of the requirements document. Then, in succeeding iterations, features are persistently added to this base product so that by the time we have a final product that satisfies all requirements, we will have that product. The product is developed and improved in stages by our team.
- As we move through the different iterations of the development process, the software product’s functionality will gradually improve.
- Frequently, people will refer to it as the cyclic model. The initial phase is followed by several phases that repeat themselves, with the expectation that there will be some improvement with the successful completion of each phase.
- The suggestions and comments of customers are easily incorporated into this model. In the conventional waterfall model, there is no provision for feedback pathways; consequently, there is no mechanism for error correction. Nevertheless, in the iterative waterfall model, there is a feedback channel that allows for the correction of errors, and these changes are propagated in subsequent phases. The feedback channel extends from one phase to the step that came before it.
Process of Iterative Model
The waterfall model that was in use before the iterative model was developed was intended to be improved by its replacement, the iterative model. The waterfall model is an SDLC model that follows a linear path, whereas the iterative model follows a more circular path. After the first stage of the process of requirement planning has been finished, some of the subsequent stages will be repeated. The quality of the final product as a whole is improved along with the cycles as they are worked through and put into effect.
- The first step is to make plans for the project. It serves the purpose of mapping out the specific requirements. Whether we’re talking about the hardware or the software. In this stage, we will also prepare for the stages that will come after this one.
- The data will then be analysed as the next step. It is done so that it can be decided whether or not the project has been equipped with the necessary models and business logic.
- In this part, we will break down the expected deliverables into more specific requirements for the business. During the first stage of the project, a Requirement Management Plan is drafted to define how the requirements will be documented, communicated, tracked, and altered over the course of the remainder of the undertaking.
- During this stage, the course that the project will follow throughout its duration as well as the utilisation of the project strategy documents are both defined.
- After that comes the stage of design. At this point in the process, the team working on the project should have a comprehensive set of requirements to work from, as well as the path that the project is intended to follow and a conceptual design of the systems involved.
- Even if the project is small and the requirements for the project are straightforward, there is still a mental design process that occurs between understanding the requirements of the project and beginning to build it. This is true even if the project is simple and the requirements for the project are straightforward. As the scope of the project expands and its requirements become more stringent, design assumes an increasingly critical role. During the Design stage of the project, many different options for completing the task are investigated. The possibilities for solutions have been reduced. After that, the method of constructing the system that is determined to be the most effective and efficient is selected.
- During the stage of analysis, the technical requirements for the project are broken down into minute detail to accommodate any needs that are discovered.
- Implementation and coding come together in the fourth stage of the process. At this stage, each and every requirement, as well as the planning and design plans, are put into action and coded. When we get to this stage of the project, we will begin the physical construction of the system.
- It is now time to begin writing the code for the programme that will be used in the project.
- The testing phase is the fifth and final stage. At this point, the currently active build iteration is evaluated with respect to a number of criteria and standards to determine whether or not it satisfies those criteria. The purpose of these testing procedures is to determine whether or not our system contains any errors or bugs.
- The solution that was developed for the project is being revalidated to ensure its consistency. To put it another way, it is ensured that the elimination of a single error will not result in the introduction of any additional errors into our system. When it comes to testing their system, the team has access to a wide variety of testing strategies, any one of which can be utilised by them. Testing such as performance testing, stress testing, security testing, requirements testing, usability testing, multi-site testing, disaster recovery testing, and so on are all included in this category.
- At this point, when all of these stages have been finished. An exhaustive analysis is carried out on the system that has been developed up until this point. The members of the development team as well as the stakeholders are given the opportunity to test the system and provide feedback on its many different components.
If any new requirements come up or if any errors or bugs are found in our system, we will need to go through all of these stages again. As soon as these steps have been completed. To put it another way, all of the requirements have been met, and they have been thoroughly checked. The system that is used by end users is always the most recent iteration that has been built.
When to use the Iterative Model
Use cases that benefit from employing the iterative model include the following:
- It is possible to adhere to the iterative paradigm when developing a large project by first breaking it down into smaller pieces and then developing each of those pieces in turn.
- When it is possible to understand the requirements and define them clearly at the beginning of the project.
- When it is necessary to incorporate customer feedback at every stage – The primary requirements are outlined at the outset; however, as the process of development moves forward, some functionalities are changed, and additions are suggested.
- While they are working on the project, the development team is exploring new technological avenues and expanding their knowledge in this area.
Examples Of Iterative Model Design
Below are the examples :
- User Interfaces
A film production company is required to have a bespoke system in place for the tracking of their equipment, costumes, and props. It is not common to find business sections included in documents that render project specifications for technology-based endeavours. An iterative outline strategy is utilised in order to avoid the typical scenario in which developers labour nonstop for a period of one month and produce something that customers will be unwilling to purchase. There are two meetings held each week between the users and the developers to go over the most recent system. The consumers get hands-on experience with the products and come up with new specifications based on rigorous prioritisation that reduce the number of workdays needed. In this way, the system reveals itself to be useful while simultaneously being easy to operate.
- Graphic Design
It will take the creative department of the advertising agency two weeks to produce an advertisement print for a client. They have a proposition that they will present to their customers within the next few days. Because of the amount and number of time that the deadline encompasses, they would have likely already gone through a previous series of responses from recurring customers and are confident that it will perform as expected and be confirmed by the customer.
A firm of architects quickly creates models and architectural animation to display in the client’s presence. This keeps the customer involved and makes it more likely that the company will be chosen for a particular project.
An online fashion retailer’s website is never again going to start from scratch in order to replace an existing website. On the other hand, the user interface (UI) is continuously debated, updated, and improved. Keeping track of the metrics and correlating them with changes. The development conducted by companies that have established themselves as experts on procedures that are unique to their industry.
- Urban Design
A town is responsible for assisting communities in the development of ten-year plans that serve as both strategies and tactics. In the meantime, it moves on to the execution phase; city planners try something on a smaller scale and collect feedback before moving forward in all aspects of the programme. For instance, a particular layout of the living street pattern might be tested out in a location for a period of a year before the utilisation of it is improved further.
Advantages of the Iterative Model
- Inherent Versioning: The fact that the vast majority of software development life cycles will include some type of versioning, which will identify the software’s release stage at any given stage, should not come as a surprise. The iterative model, on the other hand, makes this process significantly simpler by ensuring that each subsequent iteration is an incrementally improved version of the iterations that came before it. Additionally, in the event that a new iteration fundamentally breaks a system in a catastrophic way, a previous iteration can be quickly and easily implemented, also known as “rolled back,” with little to no losses; this is a feature that is particularly useful for post-release maintenance or web applications.
- Rapid Turnaround: Although it may appear that each stage of the iterative process is similar to the stages of a more traditional model such as the waterfall method — and as a result, the process will take a great deal of time — each stage can be effectively compressed into smaller and smaller time frames; whatever is required to meet the requirements of the project or organization. This allows the process to be tailored to meet the requirements of the project or organisation in a manner that is more efficient This allows the iterative process to be tailored to meet the requirements of any given project or organisation. The first time through all of the stages may take some time, but after that, each subsequent iteration will be faster and faster. This lends itself so well to the agile name and makes it feasible to decrease the life cycle of each new iteration to a couple of days or in some cases even hours.
- Suited for Agile Organizations:If you have a huge organisation with hundreds of team members, the waterfall approach may work effectively for you. The iterative model, on the other hand, begins to flourish when it is in the hands of a smaller, more agile team. Several team members can conduct the entire “iteration process,” from planning and design to implementation and testing, with minimal or no assistance or feedback from outside sources, especially when contemporary version control systems are utilised. This is especially true when the capabilities of version control systems are paired with those of other contemporary technologies.
- Easy Adaptability: Another key benefit of the iterative model is its quick adaptability to the project’s shifting requirements as well as the whims of the client. This capability relies on the fundamental strength of frequent, continuous iterations that are released on a regular basis. Even significant alterations to the implementations or underlying code structure (such as the introduction of a new database system or service, for instance) can frequently be made quickly and affordably. This is feasible due to the speed with which any unfavourable changes can be identified and returned to a previous version of the code.
Disadvantages of the Iterative Model
- Costly Late-Stage Issues: When using an iterative model, there is a chance that an unanticipated problem in the design or underlying system architecture will surface late in the project. This is not necessarily a problem for all projects; however, due to the minimal initial planning that occurs before coding and implementation begin, when using an iterative model, there is a chance that this will occur. The solution to this could potentially have disastrous effects on the project’s budget and schedule as a whole and would call for numerous additional iterations to address just one issue.
- Increased Pressure on User Engagement: The iterative model frequently requires user engagement throughout the entire process, in contrast to the waterfall model, which places the majority of the emphasis on nearly all user and client engagement within the initial stages of the project during a short crunch time period. This can occasionally be an unfortunate obligation because each new iteration will probably need testing and user feedback in order to accurately assess any changes that might be required.
- Feature Creep: Not only is user feedback required throughout the iterative model’s development process, but this also inherently means that the project may be subject to undesirable feature creep. This happens when users see the improvements made in each iteration and are inclined to keep submitting fresh requests for new features to be included to future releases.
Question: Where is iterative model used?
Answer: The iterative model is utilised in a variety of settings, some of which are detailed in the list that follows:
- when each and every one of the system’s requirements has been completely outlined and comprehended.
- The primary requirements are laid out, but as the development process moves forward, certain functionalities and suggested additions are subject to transformation.
- The development team is gaining knowledge of and experience with a new technology while they work on the project at the same time.
Question: Is waterfall model iterative?
Answer: The iterative model is very similar to the waterfall concept; the only significant difference is that the iterative waterfall enables you to return to a previous phase in order to update the criteria and make some changes, if necessary. The waterfall concept is also known as the sequential model.
Question: What are the limitations of the iterative model?
The iterative model has a number of important limitations, which are listed below:
- Skill analysis calls for personnel with a very high level of qualifications.
- This method may not be useful for projects of a less significant nature.
Banks, F. (2022, July 13). Iterative Model: What Is It And When Should You Use It? https://blog.airbrake.io/blog/sdlc/iterative-model
Rana, K. (2021, November 23). Iterative Model in Software Engineering. ArtOfTesting. https://artoftesting.com/iterative-model
Iterative Model – Software Engineering. (2022, August 22). InterviewBit. https://www.interviewbit.com/blog/iterative-model/