### Instruction:

Extract the cause and effect entities from the following sentence:
Both upmass and onboard stowage resources are constrained resources for Gateway; therefore, hardware items to be maintained must be defined at the lowest level possible, balancing mass and volume of the items with crew time required for repair

### Assistant:

CAUSE_1: hardware items to be maintained
EFFECT_1: must be defined at the lowest level possible
EFFECT_2: balancing mass and volume of the items with crew time required for repair
NOT_RELEVANT: Both upmass and onboard stowage resources are constrained resources for Gateway
KEYWORD: therefore
VARIABLE: mass and volume of the items with crew time required for repair
CONDITION: balancing

