Utility procurement resumed in 2003 and has been guided by the biennial Long-Term Procurement Plans (LTPP) beginning in 2004, D0412048. The LTPP allows for greater head-to-head competition and provides guidelines on all-source solicitations, resolves cost recovery issues, and begins integrating renewables procurement with general procurement. Resource Adequacy promotes infrastructure investment by requiring that Load Serving Entities procure capacity so that it is available to the California Independent System Operator (CAISO) when and where needed.