# SSI

SSI may refer to:

## Companies

* Safe Superintelligence Inc., an American artificial intelligence company
* Sahaviriya Steel Industries, Thai steel company
* Samsung Semiconductor Inc., a Korean electronics company
* Silicon Systems Inc., an American company that produced integrated circuits.
* Space Services Inc., a team of companies investigating new commercial opportunities in space
* Strategic Simulations Inc, computer gaming company that produced war and simulation games from the mid-1980s to late 1990s.
* Survey Sampling International, a global provider of sampling solutions in marketing research program
* SSI Group, a healthcare revenue cycle company; see Rosa Lavín

## Science and technology

* Soil-structure interaction, the interaction between soil and structures (e.g. buildings), especially in seismic engineering
* Solid State Interlocking, the brand name of a railway signalling system developed in the 1980s in the UK
* Solid state ionics, the study of ionic-electronic and ionic conductors (solid electrolytes) and their uses
* SteadyShot Inside, a sensor-based camera image stabilization system by Sony

### Computing

* Serializable snapshot isolation, a way to allow multiple concurrent transactions to see consistent information when making changes to a database
* Server Side Includes, a server-side scripting language used on the Web
* Self-sovereign identity, the user has a means of generating and controlling unique identifiers as well as some facility to store identity data.
* Shared Source Initiative, a source-available software licensing scheme by Microsoft
* Simple Sensor Interface protocol, a simple communications protocol designed for smart sensors
* Single sign-in, a specialized form of software authentication
* Single system image, a cluster dedicated operating system
* Small-scale integration, a type of integrated circuit
* Synchronous Serial Interface, a serial interface standard for industrial applications

### Medicine

* Stress–strain index, a measure of bone strength
* Surgical site infection
* Sliding scale insulin, fast- or rapid-acting insulin only given subcutaneously

## Economics and government

* Standing settlement instructions, payment processing and settlement information about financial institutions
* Strategic sustainable investing, an investment strategy that recognizes financial value in transitional leadership towards sustainability
* Supplemental Security Income, a United States federal government program
* Scottish statutory instrument, a form of secondary or subordinate legislation in Scotland
* Sensitive security information, a category of sensitive information under the US government's information sharing and control rules

## Military and police

* Selective Service Initiative, a form of military conscription in the United States
* Senior station inspector, a rank in the Singapore Police Force
* Shoulder sleeve insignia, formation insignia used by the United States Army
* Soldier Support Institute, a U.S. Army organization
* Staff Sergeant Instructor, an appointment in the British Army
* State Security Investigations Service, former Egyptian agency
* Strategic Studies Institute, the US Army War College institute for geostrategic and national security research and analysis
* Attack Submarine (Diesel Air-Independent Propulsion) (hull classification symbol: SSI), a submarine classification type used by the US Navy
* Subsecretaria de Inteligência, the Brazilian intelligence agency until 1995

## Organizations

* Sano Sansar Initiative, a global youth organization
* Scuba Schools International, a diver training organization
* Software Sustainability Institute, a UK-based, academic software organisation
* Space Science Institute, an American nonprofit organisation based in Boulder, Colorado
* Space Studies Institute, an American non-profit organization based in Mojave, California
* Spastics Society of India, former name of Able Disable All People Together
* Spatial Sciences Institute, a professional body in the Asia-Pacific region
* Statens Serum Institut, the Danish State Serum Institute
* Swedish Radiation Safety Authority (Statens strålskyddsinstitut), a Stockholm-based regulatory and research government agency
* Students Supporting Israel, a network of pro-Israel student organizations in North America and the United Kingdom
* Swedish Society for Interlingua, a society that encourages the active use of Interlingua in Sweden

## Other uses

* Socio-scientific issues, controversial social issues which relate to science
* Solid State Ionics, a peer-reviewed scientific journal
* Solid State Intelligence, a malevolent entity described by John C. Lilly
* South Sandwich Islands, a chain of uninhabited volcanic islands in the South Atlantic Ocean, that is part of the South Georgia and the South Sandwich Islands British Overseas Territory
* St. Simons Island, a barrier island on the coast of Georgia, US
* Star of the Solomon Islands, the most senior award made by the government of the Solomon Islands
* Sustainable Society Index, a tool for assessing the sustainability of 151 assessed countries