@startuml

class ResearchGroup{}

class Department{}

class Researcher{}

class Project{}

class WorkPackage{}

class WorkPackageLeader{}

class Service{}


Department "1" -- "0..*" ResearchGroup
ResearchGroup "1" - "0..*" Researcher
(ResearchGroup,Researcher) .. ResearchGroupMember 
Project "1" -- "1..*" WorkPackage
WorkPackage "0..*" - "0..1" ResearchGroup 
(WorkPackage,ResearchGroup) .. WorkPackageLeader
ResearchGroupMember "1..1" -- "0..*" Service 
WorkPackageLeader "1..1" -- "0..*" Service 

@enduml