 the us simul studi inform storag retriev system previou applic simul storag retriev system isr overli restrict scope fail consid environ system oper thi paper consid isr subsystem larger system includ user funder retriev system the three compon form close-loop feedback system user respons influenc fund oper isr attempt satisfi user finit budget alloc reward-cost theori basi describ user behavior an industri dynam model develop simul isr user funder behavior univers department librari isr compon the analysi produc discuss 