The first reason to think about production during implementation is better manufacturability. Ultimately you want to produce the product in a certain quantity. For this you want to set up a process that is as smooth as possible, in which simple assembly and cost play an important role. The sooner you pay attention to this, the higher the chance your product will be easier to produce.
A PCBA or printed circuit board must not contain any manufacturing defects. Therefore, a PCBA must be made testable. Before you start producing a prototype, write a Test Specification. Here you will find how to test all the functionalities of your PCBA. To make the PCBA easy to test, add test points to, for example, circuits and power lines.
While writing the Test Specification you will probably discover a lot of points where you want to add a test point. Later, when the product is made in larger batches and the product is automatically tested by, for example, an FCT, these test points come in handy. This means you don't have to place them in all kinds of places where it no longer fits. The manufacturer of your test tooling does have restrictions for the spacing of, for example, a bed-of-nails. So once again: consult with your manufacturers in advance.
If you think about production early, you can save a lot of costs. At the start of the process you are faced with a world full of possibilities. The costs of these changes and possibilities are still low. As the process progresses, your options diminish and changes become more expensive. So try to make your scope as wide as possible at the beginning of your design process. The wider your design scope, the more variables you can oversee and the cheaper you can make a product.
As the process progresses, your options diminish and changes become more expensive.
Thinking about production during the implementation phase has many advantages. Even if your project may never reach a later stage, it's important to think about it. The product will be easier to test, easier to produce and ultimately cheaper. We often only think about the assembly, the choice of certain materials or the omission of them at the end of the development project. Unfortunately, your options are already limited and the costs for the measures taken can be considerable. It also takes a lot of time and ultimately has an impact on your time to market.
In short; if you include possible production issues in your first iteration, your options will be plentiful and the costs are relatively low. A good starting point for a successful product!