When a tech is assigned to a lab, he$/$she is also assigned an instrument for that

rotation. Techs are rotated through the various labs. Instruments are taken

offline sometimes for service. Labs are sometimes closed for cleaning. A lab is

staffed by at least $1$ tech. An instrument can be assigned to different labs over its

life span.

Convert this to an EERD with an associate entity. You must include the correct

optionality and cardinality conversions.