1 EXHIBIT 21.1 SUBSIDIARIES OF THE REGISTRANT JURISDICTION OF SUBSIDIARY INCORPORATION Applewhite & Gittleson California Benton International, Inc. California Deutsche Perot Systems GmbH Germany Icarus Consulting A.G. Switzerland Icarus Consulting GmbH Germany perot.com inc. Delaware Perot Systems A.G. Switzerland Perot Systems Asia Pacific Pte Ltd. Singapore Perot Systems, B.V. The Netherlands Perot Systems (Canada) Corporation Canada Perot Systems Communication Services, Inc. Delaware Perot Systems Europe (Energy Services) Limited United Kingdom Perot Systems Europe Limited United Kingdom Perot Systems Financial Services Corporation Delaware Perot Systems Healthcare Services Corporation Delaware Perot Systems Holdings Pte Ltd. Singapore Perot Systems International, Inc. Delaware Perot Systems Investments B.V. The Netherlands Perot Systems Investments Limited United Kingdom Perot Systems Investments No. 2 Limited United Kingdom Perot Systems (Japan) Ltd. Japan Perot Systems Luxembourg S.a.r.l. Luxembourg Perot Systems Monaco S.A.M. Monaco Perot Systems S.A. France Persys Ireland Limited Ireland PS Information Resource (Ireland) Limited Ireland PSC Government Services Corporation Delaware PSC Health Care, Inc. Delaware PSSC Acquisition Corporation Delaware RothWell International, Inc. Texas Security Services, Inc. d/b/a Park Central Security Services, Inc. Delaware Stamos Associates Inc. California Syllogic Ireland Limited Ireland Syllogic B.V. The Netherlands The Technical Resource Connection, Inc. Delaware Time 0 Inc. Delaware TXZ North America, Inc. Delaware