Process-Architecture-Optimization is a development model introduced by Intel for their mainstream microprocessors in 2016 following the phase-out of their Tick-Tock model. The change is a result of the increase in cost and complexity of advancing lithography processes in the past decade. Under the new model the amount of time utilized for any given process technology is lengthened as Moore's Law slows down.

Under the Process-Architecture-Optimization Model:

• Process - With each process, Intel advances their manufacturing process technology in line with Moore's Law. Each new process introduces higher transistor density and a generally a plethora of other advantages such as higher performance and lower power consumption. During a "process", Intel retrofits their previous microarchitecture to the new process which inherently yields better performance and energy saving. During a "process", usually just a few features and improvements are introduced.

• Architecture - With each architecture, Intel uses the their latest manufacturing process technology from their "process" to manufacture a newly designed microarchitecture. The new microarchitecture is designed with the new process in mind and typically introduces Intel's newest big features and functionalities. New instructions are often added during this cycle stage.

• Optimization - With each optimization, Intel improves upon their previous microarchitecture by introducing incremental improvements and enhancements without introducing any large charges. Additionally the process itself enjoys various refinements as it matures. (For example with Kaby Lake, an optimized process called "14 nm+" is used. The enhanced process had a number of transistor-level modifications done to it (e.g. taller fins) allowing for higher frequency at identical voltage levels.)

Schedule

Intel PAO Schedule
Cycle	Process	Introduction	Micro­archi­tecture
Process	14 nm	2014	Broadwell
Architecture	14 nm	2015	Skylake
Optimization	14 nm	2016	Kaby Lake
Optimization	14 nm	2017	Coffee Lake
Process	10 nm	2017	Cannonlake
Architecture	10 nm	2018	Icelake
Optimization	10 nm	2019	Tigerlake