NOVELTY - Method for starting up hydrogen-generation assembly having hydrogen-producing region (HPR) and pressure swing adsorption (PSA) assembly, involves supplying feedstock to hydrogen-generation assembly and mixed gas stream to PSA assembly; utilizing HPR and PSA shutdown sequences from HPR hydrogen-producing state and PSA hydrogen-purifying state to dormant state; and utilizing HPR and PSA startup sequence from dormant states to HPR hydrogen-producing state and PSA hydrogen-purifying state, where further utilizing PSA startup sequence includes partially concurrently with HPR startup sequence.    USE - To produce energy in hydrogen-generation assemblies or fuel cell systems e.g. electrochemical fuel cells used in motor vehicles, recreational vehicles, boats, residences, commercial offices or buildings, neighborhoods, tools, lights and lighting assemblies, appliances, computers, industrial equipment, signaling and communications equipment, radios, electrically powered components on boats, battery chargers and even the balance-of-plant electrical requirements for energy-producing systems.    ADVANTAGE - The pressure swing adsorption (PSA) assembly is in contact with hydrogen source to reduce the startup time of the PSA assembly. The method includes shutdown procedures that place the PSA assembly in controlled dormant state when not in use, and startup procedures to quickly begin producing pure hydrogen gas which is then controlled to enable startup to proceed quickly, thus reducing overall startup time of hydrogen-generation assembly and energy-producing assembly. The use of mixed gas stream is to pressurize PSA assembly which allows PSA assembly to produce its own purge gas and startup without need for either hydrogen storage device or purge gas source.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for hydrogen-generation assembly comprising fuel processing system with hydrogen-producing region; pressure swing adsorption (PSA) assembly to receive mixed gas stream and separate into product hydrogen stream and byproduct stream, where product hydrogen stream contains greater purity of hydrogen gas, greater concentration of hydrogen gas, and lower concentration of other gases than byproduct stream; and hydrogen source other than hydrogen-producing region to provide hydrogen gas to PSA assembly during startup of PSA assembly.    DESCRIPTION OF DRAWING(S) - The figure shows flowchart of operating sequence used with pressure swing adsorption (PSA) assemblies.