Three of the leaders in selling the products fueling the e-business craze--EMC Corp., Hopkinton, Mass.; Cisco Systems Inc., San Jose, Calif.; and Oracle Corp., Redwood Shores, Calif.--announced Monday a marketing alliance intended to simplify the implementation of e-business infrastructures for their customers. Called ECOstructure, the initiative includes the establishment of a joint development center to create technical configuration blueprints for e-business schemes relying on networking, storage and database software. Consulting firm KPMG L.L.P. said it plans to use ECOstructure blueprints for assessing its clients' e-business needs.