This rule
main: producer.o consumer.o AddRemove.o
$(COMPILER) -pthread $(CCFLAGS) -o producer.o consumer.o AddRemove.o
is wrong. It says to create a file named producer.o (with -o producer.o), but you want to create a file named main. Please excuse the shouting, but ALWAYS USE $@ TO REFERENCE THE TARGET:
main: producer.o consumer.o AddRemove.o
$(COMPILER) -pthread $(CCFLAGS) -o $@ producer.o consumer.o AddRemove.o
As Shahbaz rightly points out, the gmake professionals would also use $^ which expands to all the prerequisites in the rule. In general, if you find yourself repeating a string or name, you're doing it wrong and should use a variable, whether one of the built-ins or one you create.
main: producer.o consumer.o AddRemove.o
$(COMPILER) -pthread $(CCFLAGS) -o $@ $^