What does iterative mean in project management?
The iterative process in detail
It is important that the project plan and / or the overall goal of the project are defined. This involves determining what requirements need to be met to keep the project within scope and what the end state should be. The question arises as to how long the project will take, who will be involved and what risks may occur. The time required for the project is difficult to predict but can be roughly estimated based on the requirements.
The first iteration is then drafted. These results bring you closer to the project goal and can represent individual functions or a complete project. The results produced are then tested, whereby feedback is particularly important. Based on this, the extent to which changes are necessary is assessed, as changes should only be integrated if they bring the project goal closer. If it is decided that something needs to be changed, it is incorporated into the next iteration, tested again and feedback is obtained. This process is carried out until you are satisfied with the result.
Iterations are also used in Scrum. These are Sprints, but they cannot be equated 1:1 with iterations. In contrast to iterations, the aim of a Sprint is not to improve a function, but to achieve a specific increment, a tested, usable or saleable sub-product. The product that is created at the end of a Sprint should therefore be ready for use.
The agile framework Extreme Programming also works with iterations, which represent development cycles. The main aim is to speed up the development process and ensure optimal customisation. In this way, continuous progress can be made and specific goals can be achieved.
As already mentioned, the iterative approach is not just an agile principle. Feedback loops can also be used in traditional software development. There, they can occur in all phases of planning, implementation, verification and customisation. An iteration can look like this:
1. Iteration takes place in a specific project phase, e.g. in research: an experiment is intended to test a specific hypothesis and the phase must be planned before it is carried out. The implementation of the phase with the sub-goals is planned by a researcher and then forwarded to a second person for cross-checking. This second person then gives feedback that relates, for example, to the sustainability of the project. This feedback is then incorporated by the researcher and checked again. This continues until the result is satisfactory and it is possible to move on to the next phase.
2. Iteration in individual subtasks of the development phase: The development phase consists of three subtasks. The third task will give you feedback that something is not quite right. Therefore, a step back is taken and the subtask is repeated. This continues until the desired result is achieved.
3. Iteration as the interplay of several phases: A product is developed, immediately built and tested. After testing, the product is revised with the help of feedback and is therefore back in the development phase. This development is then built and tested again until the desired quality of the final result is achieved.
Iterative versus incremental
An iterative process uses feedback and information to gradually improve an existing result that cannot yet be brought to market as a stand-alone product.
In contrast, an incremental process delivers an independent product, an increment that can already be used and adds new functionalities to a result during the course of the process. It is a gradual improvement or expansion of the scope that, among other things, enables a rapid market launch.
In most cases, teams use both methods. In the incremental process, a prototype is created that is iteratively revised after delivery and feedback.
A small example will illustrate the difference:
A biro is to be manufactured and marketed. In both the incremental and the iterative approach, a prototype is produced first.
In the iterative approach, various aspects of the biros are improved: if the feedback shows that the ballpoint pen does not last long enough, the ink cartridge is replaced so that the biros last longer. The feedback is then analysed again and the next aspect is improved.
With the incremental approach a new function is added immediately: A green ink cartridge is added next to the blue one, so that the biros now write in two different colours.
By combining these two methods, the optimum can be achieved from the project. In the example, this means that a new ink cartridge is first used to increase customer satisfaction and then a new function, namely the green ink cartridge, is added. In this way, the iterative approach is combined with the incremental approach.
Advantages and disadvantages of the iterative approach
Another advantage is that the iterative approach also enables parallel work, depending on the method chosen, as the phases do not always build on each other and individual team members can therefore work on several things at the same time. However, it can also happen that you miscalculate and suddenly have too few staff to work on the many different projects.
However, this approach minimises risk by allowing problems to be identified and addressed immediately. In addition, the testing phases allow immediate feedback from users. This enables immediate response to customer needs and ensures that the project can be completed successfully.