> For the complete documentation index, see [llms.txt](https://monasheng.gitbook.io/zerotohero/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://monasheng.gitbook.io/zerotohero/cots-parts-zero-to-hero.md).

# COTS Parts Zero to Hero

Commercial-Off-The-Shelf (COTS) is a designation used to describe components, subsystems, and products that are commercially available, standardised, and manufactured at scale for use across many applications, rather than being designed and built for a single, bespoke purpose.

COTS parts exist because they solve common engineering problems repeatedly, reliably, and economically, and because the cost, time, and risk required to develop mature components from scratch is far greater than most projects can justify.

Thomas Sowell, a well-known economist, coined a phrase that has become ubiquitous in engineering:

> “There are no solutions, only trade-offs.”

Junior design engineers are often tempted to develop bespoke solutions to every problem, in an effort to delay or avoiding facing these trade-offs head-on.

With experience, mature engineers learn that development effort is a finite and valuable resource, and that designing custom components where robust, well-understood COTS solutions already exist  increases cost, risk, and the number of potential failure modes. These choices consume time and attention that could otherwise be directed toward aspects of a design where bespoke work genuinely adds value.

This module will introduce the principles and practices of selecting and integrating COTS parts as a deliberate engineering strategy for managing trade-offs, reducing risk, and focusing effort where it adds the most value.

## Learning Outcomes

In this short course, you'll learn:

* [x] the basics of engineering product design and the overwhelming resource investment required to bring mature parts to market,
* [x] how to assess risks (to timelines, reliability, maintenance, life-cycle, and overall project success) and mitigate these with COTS parts,
* [x] how to specify COTS parts for your designs, including selecting sensible suppliers and reading datasheets, and,
* [x] the fundamentals of "jelly bean" engineering component families - common COTS parts you should generally build rather than buy.