For the different use cases, people created emulators/simulators. This page aims to reference them and leverage on existing simualtors.
In other words before creating yours, check that somebody did not already created it 
PNF Simulators
pnf onboarding
Owner: szabolcs.hutvagner AT ericsson.com
Repository: https://git.onap.org/integration/tree/test/mocks/pnf-onboarding
PNF simulator
Owner: Wojciech Sliwka
Repository: https://git.onap.org/integration/tree/test/mocks/pnfsimulator
Sniro simulator
Owner: georab AT amdocs.com
Repository: https://git.onap.org/integration/tree/test/mocks/sniroemulator
Mass PNF Simulator
Owner: Tamas Bakai
Repository: https://git.onap.org/integration/tree/test/mocks/mass-pnf-sim
PMSH PNF simulator
Owner: user-3784d
Repository: https://git.onap.org/integration/tree/test/mocks/pmsh-pnf-sim
RAN simulator
Ran simulator
Owner: Priyadharshini B
Repository: https://git.onap.org/integration/simulators/ran-simulator/
Description:
Use cases: <list of use cases using this simulator>
Misc
EMS simulator
Owner: Enbo Wang
Repository: https://git.onap.org/integration/tree/test/mocks/emssimulator
HV VES Simulator
Owner: Marek Pondel
Repository: https://git.onap.org/integration/tree/test/mocks/hvvessimulator
Netconf PNP simulator
Owner: Eliezio Oliveira
Repository: https://git.onap.org/integration/tree/test/mocks/netconf-pnp-simulator