The time for building software is highly variable and depends on its complicacy, the number of characteristics, and the chosen development methodology. A few weeks to a couple of months may be necessary for simple applications, while several months to more than one year may be required for more intricate systems. The planning and design stages are the most important and can significantly influence how long it takes. Development processes include iterative coding, testing, and refinement phases, especially under Agile methodologies that allow for more flexible and faster deployment.
On the other hand, the waterfall approach has a structured development path that can extend the timeline. Further development, such as releasing into the production environment, user acceptance test (UAT), or user testing, among others, also concur with the overall project's timeline. Basically, software construction is driven by multiple factors such as scope, the quality method used, and its ability to change concerning changing project needs. So, on average, it takes from 3 to 9 months to build software.