Hardware Development Schedule
Product development for hardware design is not just limited to system EE or RF teams but rather a highly cross-funtional and collaborative involving various teams such as validation team, mechanical product design team, factory quality team, reliability team, compliance tea ,etc.
Product design team are mainly consisting for mechanical engineers who do design the enclosure, connectors type, allowable board space and height, etc. following the industrial design outlines given by the industrial design team.
Electrical engineering team is mainly consistent of digital system EE, RF system EE, are other specialist team such as Antenna, power, and validation teams.
In short, product development is highly collaborative.
- The overall program is determined by the product road map. Generally 1 to 2 years are common for a single product.
- Typical build schedule is roughly 6 weeks to 3 months between each development stage.
This is a non-form factor proof of concept stages that involves selecting the right chipsets and verify essential hardware components on a large size of PCB boards to test basic chip interconnects and functionalities.
The main goal here is unblock software development and finalize hardware architecture selections and interconnects.
The is a form factor design board that has design with the the exact mechanical component outline (MCO) board dimensions given by the product design team.
The main goal here is validate that the within the limited board space, all hardware component can be placed and interconnects routed.
In this phase, the PCB, Antenna, and other electrical modules are fitted inside an enclosed designed by product design team.
lastly, the validation testing is started on this phase.
Engineering Validation Testing (EVT)
"EE hardware lock stage"
At this stage, all the test results from the validation team is finalized, and all necessary changes are implemented in the schematic and layout.
Ideally, this is hardware lock stage meaning that no electrical engineering design changes can be made after this stage.
However, for the product design team, they are making slight changes.
lastly, this marks the start of regulatory compliance testing.
Device Validation Testing (DVT)
"Mechanical Hardware Lock stage"
At this stage, all mechanical designs are locked.
Product is preparing for mass production.
Regulation certification is done on the hardware.
Production Validation Testing (PVT)
"Factory assembly line Lock stage"
This stage is to test to factory ramp readiness for mass production by identify any bottlenecks that slows down the assembly line unit per hour (UPH) throughput, and find the appropriate total number of assembly lines needed to meet the initial launch quantity goal.
Lastly, at this stage, the operation team takes over the product development from the design teams.
Mass product (MP)
This is the last stage for product cycle where factory is in full operation. The factory will ramp for few weeks to few months depending on expected total sales.
All products will be packaged up and shipped either via sea or air to designated regions.
Products are shipped to each retail locations by trucks and some extra time is allowed for importation paper work to be worked in for each intended regions of sales.
This is when the company announces the product and make the product officially to be on sale.
Design Release to receiving Hardware takes time.
It takes roughly two weeks from design release to start building the hardware. Moreover, it takes a week to assemble the hardware and another week to ship the product to the design team to start validation. So one would expect a month waiting before any hardware validation can be started. To worsen the situation, the EE design release is at least a or two week before the layout release allowing some headroom for layout engineers to make changes on the PCBs and review the changes with the manufactures.
In the end, in a 6 weeks building schedule, the validation and design team only has 2 to 3 weeks to test and make and design changes.
Additionally, there are always small mistakes that gets caught last minute due to reliability of components, component sourcing problems, high electronic noise that needs extra filtering, etc.
Hence, there are might be couple proto builds to get the PCB and electronic components selections and routing done correctly. And this also allows validation team to continue finding problems. Most often, validation team carries out the main test items first due to time schedule time and later changes have to be entered in the next next design stage.
There are also few EVT builds to get the form factors mechanical design done correctly such as redesigning the button, find better thermal solutions, find new connectors that is more robust, change the waterproof design design, etc.
There could be additional DVT builds to get the mechanical cosmetic color adjustment done correctly, plastic molding technic done correctly, etc. Or there worst case, a critical EE/RF design changes that need to added in due to feedback from validation or failure of a certification; often, this requires a serious of approvals up to VP level, and it should be avoid at any cost.
Summary and Conclusion
- Produce cycle takes a year or two.
- Build schedule is roughly 6 weeks to few months.
- Validation and design schedule is short due to extra time needed for layout review, manufacturer-ability review, production time, and shipment time.
- Additional builds are common in the industry in to fix small but critical problems.
As we can see that hardware design requires only few tries to get it right, and time is often very tight. When hardware leaves the factory, there is not point of return. Therefore, as a good engineer, we need to ensure all the necessary design changes and validation testing are done in the beginning stage to avoid unnecessary chaos in the later stage.