|Type||Public limited company|
|Traded as||LSE: ISYS|
|Industry||Industrial Automation, Transportation, Controls|
|Headquarters||London, United Kingdom|
|Key people||Nigel Rudd
Computer-based Automation Hardware
Railway Control and Communication Systems
|Revenue||£2,539 million (2012)|
|Operating income||£153 million (2012)|
|Net income||£99 million (2012)|
Invensys plc is a British multinational engineering and information technology company headquartered in London, United Kingdom. It was formed in 1999 through the merger of BTR plc and Siebe plc. It has offices in more than 50 countries and its products are sold in around 180 countries.
It is organised into three main divisions: Invensys Operations Management is a global industrial automation supplier with brands including Avantis, Eurotherm, Foxboro, IMServ, InFusion, Triconex, SimSci-Esscor, Skelta, and Wonderware.; Invensys Controls is a global supplier of control devices with brands including Drayton, Eberle, Eliwell and Invensys Appliance.; Invensys Rail is a major supplier of railway control equipment and software with including Dimetronic, Safetran and Westinghouse.
Invensys was formed by the merger of Siebe plc and BTR plc in 1999. From 1999 to 2004, it underwent a major restructuring programme to cut its costs as falling sales and large debts had led to the danger of its going bankrupt. A major disposal programme combined with a £2.7bn debt restructuring in 2004 saved it from collapse. During that time it bought and sold The Baan Corporation.
In March 2011, Wayne Edmunds, who had been Chief Financial Officer since 2009, was appointed Chief Executive, replacing Ulf Henriksson. According to The Financial Times, Henriksson, who had been Chief Executive since 2005, had had differences with chairman Nigel Rudd over running the company, in spite of the return to financial health under Henriksson.
Invensys Operations Management 
Invensys Operations Management is a technology, software and consulting business formed from the three Invensys industrial automation businesses – Invensys Process Systems, Wonderware and Eurotherm. Invensys Operations Management is headquartered in Houston, Texas, United States and Mike Caliel is the current President and CEO. 
Avantis provides maintenance repair and operations solutions including maintenance management, spares and inventory management, condition monitoring and procurement.
Supplier of control measurement and data recording to industrial and process consumers.
Provides control systems addressing distributed and plant operations as well as measurement and instrument systems. Instruments include Pressure Transmitters, Coriolis Flow Meters, Valve Positioners, Buoyancy Level Transmitters and Temperature Transmitters.
- IMServ Europe
IMServ Europe is a provider of carbon & energy solutions and data monitoring. IMServ was previously part of Invensys Controls.
SimSci-Esscor provides applications that help improve asset performance and utilization with integrated simulation, optimization, training, and process control software and services.
Skelta BPM is an enterprise wide Business Process Management and Advanced workflow solutions product.
Triconex provides safety and critical control systems used in a wide variety of critical applications including Emergency Shutdown, Burner Management, Fire and Gas and Turbomachinery Control and Protection.
Wonderware provides a range of software products to address production operations, production performance, manufacturing intelligence, business process management and collaboration.
Invensys Rail 
Invensys Rail Group designs, manufactures, supplies, installs, commissions and tests safety-related rail signalling, grade crossing predictors, and control systems for mainline, metro and freight railways. Invensys Rail has its headquarters in Chippenham, United Kingdom and the current CEO is Kevin Riddett. Invensys sold its Rail business to Siemens in November 2012.
Invensys Controls 
Invensys Controls is a provider of components, systems and services used in appliances, heating, air condition/cooling, refrigeration and safety products as well as building systems across a wide range of industries in residential and commercial markets. Invensys Controls is headquartered in Carol Stream, Illinois, United States and Mark Balcunas is the current CEO.
- "Preliminary Results 2012". Invensys plc. Retrieved 25 March 2013.
- "About us". Invensys. Retrieved 11 April 2012.
- Harrison, Michael (24 November 1998). "Siebe and BTR unveil plans for pounds 9.4bn merger". London: The Independent.
- "Annual Report and Accounts 2010". Invensys plc. Retrieved 26 September 2010.
- Mathiason, Nick (18 April 2004). "Good signals at Invensys". The Guardian (London).
- Wootliff, Benjamin (19 July 2000). "ING paving the way for Invensys to buy Baan". The Daily Telegraph (London).
- "Invensys sells Baan for US$135 million". Business Wire. 2003.
- "Appointment of Chief Executive". Press release. Invensys. 24 March 2011. Retrieved 29 March 2011.
- Peter Marsh and Michael Kavanagh (24 March 2011). "Invensys replaces chief executive". The Financial Times. Retrieved 29 March 2011.
- "Invensys shares tumble on profits warning". Daily Telegraph. 13 January 2012. Retrieved 15 January 2012.
- "Invensys Operations Management". Invensys.com. Retrieved 29 March 2011.
- "Senior Management". Invensys.com. Retrieved 18 March 2013.
- "Microsoft Recognizes Invensys Operations Management As Partner Of The Year". chemicalprocessing.com. 18 July 2011. Retrieved 18 March 2013.
- "Invensys Avantis website". iom.invensys.com. Retrieved 9 May 2012.
- "Eurotherm: Temperature Control, Measurement and Data Recording Solutions". Eurotherm USA. Retrieved 29 March 2011.
- "Foxboro Distributed Control System". Invensys.com. Retrieved 29 March 2011.
- "Measurement and Instrumentation". Invensys.com. Retrieved 29 March 2011.
- "Pressure Transmitters". Invensys.com. Retrieved 29 March 2011.
- "Coriolis Flow Meters". Invensys.com. Retrieved 29 March 2011.
- "Valve Positioners". Invensys.com. Retrieved 29 March 2011.
- "Buoyancy Level Transmitters". Invensys.com. Retrieved 29 March 2011.
- "Temperature Transmitters". Invensys.com. Retrieved 29 March 2011.
- "IMServ Carbon Solutions".
- "Invensys SimSci-Esscor website". iom.invensys.com. Retrieved 9 May 2012.
- "Invensys Skelta website". Skelta.com. Retrieved 29 March 2011.
- "Triconex page on the Invensys Operations Management Website". Invensys.com. Retrieved 29 March 2011.
- "Wonderware". Wonderware.com. Retrieved 29 March 2011.
- "Invensys Rail Website". InvensysRail.com. Retrieved 29 March 2011.
- "Invensys Controls Website". InvensysControls.com. Retrieved 29 March 2011.