The current and next generation of ground and space based instruments from ESO and ESA have moved observational astrophysics into an era of precision astronomy. Instruments are designed to maximize specific, high-precision science returns that push technical capabilities ever closer to their theoretical limits. In parallel, rapid advances in computational methods have unlocked the capability of relying on instrument simulations accounting for complex optical, mechanical, thermal, and other effects to achieve these high-precision science cases.

The implementation of detailed instrument modelling now spans all phases of a project: translating the high-level science requirements into a defined instrument concept, monitoring the compliance between science performance specifications and requirements during the  design and construction phases, optimizing science return through calibration, planning for science operations, and analyzing astronomical data products.

One critical component of instrument simulation is the behavior of the detectors. While many space- and ground-based projects use similar (and in some cases identical) detectors, most projects have implemented basic detector effects into their instrument simulators independently. To promote synergies between ESO and ESA projects around common detector technologies and to avoid duplicated effort, we are developing a general detector simulation framework called PyXel. This open-source python-based detector simulation framework allows scientists, engineers, and users to contribute models of various detector effects that can then be used and validated by all instrument teams using CCD, CMOS, or hybridized detectors in the optical and infrared.