May 2017 – Best Practices in Hardware Development Part II

Our experienced engineers design high-reliability electronic hardware and develop efficient test plans and procedures to streamline testing for our customers. With experience on hundreds of diverse systems, our analyses and assessments are efficient, accurate and thorough.

We continue the conversation we started last month by discussing the various phases of hardware development:

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  1. Specify: identify the need the “end item” or hardware in this case must satisfy
  2. Conceive: conceive or conceptualize how to satisfy that need
  3. Design: analyze, describe, and define with sufficient detail to progress towards a physical realization of the item
  4. Realize: manufacture, prototype, or otherwise produce an implementation of the design and demonstrate that the “as designed”, “as built” item is feasible, and operates as intended
  5. Verify and Validate: produce and compile evidence indicating the end item satisfies the need for which it was designed

 

Did you miss part one? Read it here.

Phase 1 Specify:
The most important phase in the process is that of identifying the needs of the customer and capturing those needs as a well-defined set of “design-to” requirements that define the end item in terms of functionality, performance, size, weight and other properties. It is of utmost importance that we engage the customer in the validation of the specification to ensure that what was interpreted is correct, and that the item being developed will meet the needs of the customer.

Tip: When formulating requirements, additionally consider “rainy day”, abnormal, or unexpected conditions.

Phase 2 Conceive:
In the second phase of development, multiple design concepts or alternatives are conceived and evaluated to determine feasibility in fulfilling the requirements. Consider trade-offs between different technologies, partitions, physical realizations, materials and hardware versus software. Create story boards, mock-ups, flow charts and algorithms to describe and convey what should be done, how it should behave and what it should look like. At the completion of this stage, in addition to internal review, we engage the customer in validating the chosen and refined approach such that no misunderstanding exists.

Tip: If you only consider one option you may be overly constraining the possibilities. This is where the design is truly defined.

Phase 3 Design:
This phase is where the design takes substance. Logic and functionality in programmable devices such as PALs, PLDs, FPGAs and digital ASICs are coded using VHDL or Verilog. Electrical components are calculated, evaluated, chosen, and interconnected resulting in a circuit design captured using a schematic editor. Details of an Interface Control Document (ICD) are finalized describing the interface(s) to a system or sub-system including that of hardware and software. Printed Circuit Boards (PCBs) are developed to physically arrange and interconnect components and boards. Mechanical components are modeled, assemblies and sub-assemblies are created, and detailed fabrication and assembly drawings and wiring harnesses are generated. Simulations and analysis are performed to evaluate correctness of function, stresses, tolerance stack-up, thermal capabilities and others as necessary to determine satisfaction of performance and intended functionality. Perform an in-depth review of design documentation and analysis results to solicit feedback and comments; do not simply perform a walk-through of the design presenting data.

Tip: Consider and analyze all operational modes and environmental conditions the end item is expected to encounter.

Phase 4 Realize:
This phase actually involves physically constructing the end item from the “build-to” documentation. Construction can consist of the following: bread-boarding using wire-wrapping or point-to-point wiring, PCB fabrication, PCB assembly, loading of software, configuring CPLDs and FPGAs, building harnesses and assembly of PCBs into an enclosure or larger system. Additionally during this phase, various degrees of design verification or engineering testing will occur including but not limited to: bring-alive testing, White Box testing, HW/SW and system level integration testing and debugging, dry-run requirement based testing and confidence testing such as EMIC, HALT, HASS and power transient testing.

Tip: Be meticulous, record all findings, observations, and deviations from intended operation. Identify any shortcomings, errors, or omissions in the “build-to” documentation.

Phase 5 Verify and Validate:
This phase generally includes requirements based testing and produces the evidence to the completeness and correctness of the design and the end item itself. It provides assurance that the end item has been developed according to its requirements and design data, has been correctly produced, and has achieved the objectives of the requirements.

Tip: The extent of design and end item verification will typically be determined by contractual requirements.

Omnicon engineers have cultivated these best practices in hardware development from over 30 years of experience. Our processes are based on stringent guidelines of widely accepted hardware development documents which address the entire life cycle processes for hardware intended for the most critical or vital applications. We also develop automatic test equipment geared towards lab testing, first article testing, production testing and any other testing needs. At Omnicon, we put our customers first, and our goal is to deliver the best possible product.

Tags: best practices, development, engineering, engineering services, engineers, hardware, hardware development

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