The pricing models
There are two commonly accepted billing models for offshore software engineering — pay-per-hour/time and materials and fixed-price model.A fixed-price model is perfect when you agreed on a strictly fixed budget within your company before starting any development activities. In this model, you pay for defined deliverables, and it sounds good, but it doesn't always work seamlessly in practice. To go with a fixed-price model, you should already have a clear, detailed, and realistic technical task for the entire project. Otherwise, you'll pay extra costs for all edits and any type of changes you may need to make in the process. It may bring frustration to understanding what should be done within a fixed-priced plan and what should be paid on top of it because many tasks are interconnected, and if you make even small changes in one part of the project, it will probably impact the rest of the tasks. Those companies that offer time and material billing models do this to avoid the situations listed above. In the time and material model, all tasks are estimated in hours and are paid by hour rates. This approach is more flexible for ongoing changes.