Sales and Operations Planning


S&OP is a management discipline which aims to align production volumes with an accurate sales forecast. Stakeholders work together to create a unified view of the market, and to predict demand by looking at data from ERP systems and other IT applications.  For many companies, S&OP means a weekly in-house meeting of sales, marketing, manufacturing and distribution to confirm the plan for next week. However, S&OP can grow to incorporate suppliers and distributors, and look at longer term and strategic topics.


Sampling is part of a statistical approach to quality control in production. It involves taking a measurement at regular or random intervals. The measurement can be the reading of a sensor which is built into a production machine, or it may involve taking a sample of material, and diverting it to a testing station or laboratory to take measurements.


In the aerospace sector, a satellite means an artificial satellite, which is an object placed into orbit, usually around the Earth, by human endeavour. The majority are communication and navigation devices. Other important satellite categories are earth observation, weather, and astronomical instruments. The largest artificial satellite currently orbiting the Earth is the International Space Station.

Scrap rate

Number of units produced that must be scrapped because of product defects or errors, divided by the total number of units produced by the manufacturing group over the same period, as a percentage. Given the long production cycles in the aerospace industry, it is important to minimize the scrap rate to increase the efficiency of day-to-day operations and meet tight delivery schedules.

Scrap/Rework Costs

Scrap/Rework Costs are the costs of fixing defective products so they pass quality checks including final inspection, plus the costs of parts and materials wasted during the production process.

Secondary Distribution

Secondary Distribution is the transportation of goods and materials from distribution centers to retailers, other businesses and direct to consumers.


A semiconductor is a substance with conductive properties which can be altered with electricity; it can be both a conductor and an insulator. Silicon performs as a semiconductor when chemically combined with other elements. Complex electronic circuits can be built into the surface of a thin layer of silicon-based semiconductor. The continuing development of semiconductor technology is a foundation for the electronics and high-tech industry sectors.

Sequence Control

Sequence Control is (1) The control of a series of machine movements, with the completion of one movement initiating the next. The extent of movements is typically not specified by numerical input data. (2) Control of the logic of machine operations, such as the start-up sequence of a complex machine, which may require lubrication and cooling systems to be running before a main motor is started.


A servomechanism includes a controller which drives a motor to move a mechanism so that the position, speed or some other characteristic of the mechanism matches an input signal. The distinctive feature of a servomechanism is that it uses feedback from the mechanism, so it is classified as a closed loop control.


A servomotor is the electrical motor used in a servomechanism. Control inputs such as rotation speed and angular position are typical.


Commonly confused with sewerage, sewage is waste from domestic households (and in some areas industry and commerce) that is carried away by a network of pipes.


Commonly confused with sewage, sewerage is the network of pipes used to transport sewage away from its source. Also known as the waste-water system.

Shale Gas Extraction

Shale gas extraction is the process of extracting natural gas from geological rock formations known as shale. In the 20th century, shale gas extraction was not profitable. In the 21st century, fracking, new horizontal drilling technologies, and new extraction methods, coupled with higher energy costs, have together made shale gas extraction a reasonable commercial proposition.


In logistics, a shipper is the company or person who owns or controls the freight and arranges for its transportation.

Shop Floor Control System

A Shop Floor Control System is designed to schedule, execute and track work orders through manufacturing. It may be part of a larger enterprise system or standalone. It will provide methods for shop floor based personnel to receive work orders and schedules, then apply predefined manufacturing procedures (called routings), and some local decisions about scheduling, to execute the work orders.

Shop Floor Data Collection


SFDC gathers, stores and communicates data from plant equipment and instruments. It is usually automated, but can be manual. SFDC often focuses on tracking progress of materials through the plant, but its scope can include performance, maintenance, quality and operator data.

Silicon Chips

A Silicon Chip consists of an integrated circuit inside a protective covering with electrical connectors. A very common arrangement is a gray, rectangular protective case, with metal connector legs. This type of silicon chip can be pushed into a suitable socket on a PCB.


Used mainly in the automotive sector, SILS can expand to Sequenced In Line Supply, Supply In Line Sequence, and Synchronized in Line Supply, and is often used to mean the same as Just in Sequence (JIS) and In Line Vehicle Sequencing (ILVS). The SILS concept is that messages are generated as the vehicle moves along the production line. These messages trigger demand for the components which will be needed for the next several assembly steps. A successful SILS system will deliver the components just in time, presented to machines and operators in the order they will be used.


A Simulation system mimics certain characteristics of one or more physical objects, even when the objects exist only as a concept or specification. In industry, computer systems are used to simulate a diverse range of characteristics and objects, for example (1) strength of a mechanical component (2) airflow to cool an electronic circuit (3) throughput of a set of production machines (4) behaviour of a mechanism in motion. Engineers use simulation to help design and improve products and systems without having to build and test prototypes. Operators use simulation for training, for example, to learn how to operate machinery.

Six Sigma Methodology

Widely referred to as ‘Six Sigma’, the six sigma method started in production and has been developed as a business management strategy. Six sigma enjoys widespread application in many industries. It seeks to ensure that every process delivers stable and predictable results by removing the causes of errors. It recognises that every process has a degree of variation, and expects the variation to be measured, and the causes of variation to be understood. The method quantifies the allowed variation using the statistical term sigma – six sigma in effect means 3.4 defects per million opportunities.

Software as a Service


Software as a Service means the software being used is running on servers which belong to someone else. So a key benefit of SaaS is that a user organization does not have to invest in computers and system administration to be able to use the software. Many SaaS applications are available through any web browser. They often are priced on a pay-per-use basis. The application is usually run in the cloud, but in all cases the provider takes responsibility for server hardware and software support and maintenance.

Solid Modelling

Solid Modelling (also 3D solid modelling) is a software technology which allows computer systems to handle data which represents a 3D object. Solid modelling enables software applications to create, manipulate, visualize and analyze objects which only exist as computer data, including objects with curved surfaces and complex internal structures. Applications can use data from the real world (such as photos or Lidar scans) to create solid models; and they can translate solid model data into instructions for production machines (including 3D printers) to make physical representations of the models.

Solid Modelling

Solid Modelling (also 3D solid modelling) is a software technology which allows computer systems to handle data which represents a 3D object. Solid modelling enables software applications to create, manipulate, visualize and analyze objects which only exist as computer data, including objects with curved surfaces and complex internal structures. Applications can use data from the real world (such as photos or Lidar scans) to create solid models; and they can translate solid model data into instructions for production machines (including 3D printers) to make physical versions of the models.

Space Vehicles

Space vehicles are designed to carry people in space. The Space Shuttle, the International Space Station, the Soyuz spacecraft and the Chinese Shenzhou craft are primary examples of space vehicles.

Special Purpose Acquisition Company

A special purpose acquisition company (SPAC), is a shell corporation listed on a stock exchange with the purpose of acquiring a private company, thus making it public without going through the traditional initial public offering process.

Spot Market

A Spot Market is a commodities or securities market in which goods are sold for cash and delivered immediately. Sellers and buyers of oil, gas and electricity generally structure their business using (mainly) long term contracts, then use the spot market to make day-by-day or hour-by-hour adjustments. In this way, spot markets help balance supply and demand, even though spot market prices can be volatile.

Standard Industrial Classification


Established in the US in 1937, SIC codes are used to classify types of industry. Other countries and regions have adopted and adapted SIC. The US replaced SIC with NAICS (North American Industry Classification System) in 1997. The EU uses NACE (nomenclature statistique des activités économiques dans la communauté européenne) and there is an international version maintained by the UN (ISIC). The codes have changed over the years, largely to ensure new industries have a place in the scheme (software development did not exist in 1937).  Concordance tables allow users of the various systems map between them. Governments generally require companies to self-classify on tax returns.

Statistical Process Control


SPC is a data driven approach for monitoring and controlling a process or production method. It involves collecting and analyzing data about a process. By using statistical techniques, the analysis can go beyond a simple pass/fail test, and identify drifts in a process before the drift is large enough to produce non-compliant results. SPC is often implemented using charts for operators to check. In advanced systems, adjustments are made automatically when readings indicate that a control limit is being approached.

Statistical Quality Control


SQC applies probability and statistical techniques to ensure products conform to requirements. It is essential when destructive testing is the only way to check a product, and it can improve cost effectiveness of inspection and testing in many environments.

Stock Keeping Units


Used universally in consumer goods and retail industries, an SKU is an identifier for every item that is maintained on stock or may be ordered. Multiple SKUs are used to cater for all the variants of the products and the different package size in each range.

Structured Analysis and Design Technique


SADT is a method to define and describe a system. It originated as a software engineering methodology in the 1970s. It defines a graphical notation for data models and activity models, and can be used for organization and workflow systems as well as technical systems. The IDEF0 method was derived from SADT.


Styrenics is a group name for all polymers based on styrene, which is made from benzene. Polystyrene is well known example, with applications in industrial, consumer and food packaging, as well as small and large electrical appliances, building insulation, fiberglass, electrical and electronic devices, household appliances, car components and toys.


A subsidy is a benefit given to an individual, business, or institution, usually by the government. It is usually in the form of a cash payment or a tax reduction. The subsidy is typically given to remove some type of burden, and it is often considered to be in the overall interest of the public, given to promote a social good or an economic policy.

Supervisory Control

(1) As a general term, Supervisory Control means the use of microcomputers and workstations to accomplish operator interface, data acquisition, process monitoring, and some degree of production control. (2) In chemical processing, Supervisory Control is the next step in automation after Regulatory Control (RC). RC maintains a process parameter (for example, temperature) when an operator sets the required value. In Supervisory Control, a computer may change the required value over time, for example for a reaction which needs a smooth change of temperature over a time period.

Supervisory Control and Data Acquisition


SCADA is a system architecture for high level control of manufacturing processes. SCADA systems consist of a network of computers and Human Machine Interfaces (HMIs). SCADA systems use factory networks to communicate with devices such as programmable logic controllers (PLCs) and other remote items such as sensors to perform their Data Acquisition and Control functions.

Supply Chain

A Supply Chain transforms and moves a product (and/or service) from the initial source of raw materials (and/or capability) to the final customer.  It involves a complex network of organizations, people, technology, activities, information and resource.

Supply Chain Execution


SCE is the optimized process of fulfilling demand for highest customer satisfaction with minimal cost. This function plans, schedules and controls the flow of goods and information from point of demand to customer delivery by tightly integrating channel demand, distribution and warehousing operations and inbound and outbound transportation.

Supply Management/Supplier Relationship Management


Supply Management is also referred to as purchasing or procurement. This function oversees corporate buying of materials both for use in production and other items. It may also handle purchasing of equipment assets, and coordinate inbound logistics and inventory management. Software applications known as Supplier Relationship Management systems are used by Supply Management teams to handle supplier performance and contracts (including costs, quality, on-time delivery, documentation and standards).

Supply-Chain Optimization

Supply Chain Optimization is a management process to identify the best strategy for relationships among the various elements of the supply chain including manufacturing plants, distribution centers, points of sale. Sources of demand, sources of raw material, relationships across product families and other factors must also be considered.

Supply-Chain/Logistics Systems

A class of manufacturing software designed to optimize scheduling and other activities throughout the supply chain – or value chain – including transportation and distribution functions.

Surface Acoustic Wave Filters


SAW devices (including SAW filters) can be built using semiconductor manufacturing processes. They integrate a loudspeaker-like device and a microphone-like device into a piezoelectric layer. Electric signals to the ‘loudspeaker’ generate waves in the material. The waves travel through the material and are detected by the microphone-like device. The difference between the input and output signals can measure mass and other mechanical properties of materials in contact with the SAW device. SAW devices designed as filters are widely used in cellphones and garage door opener remote controls.

Surface-Mount Technology


SMT allows silicon chips to be built without the widely recognised metal legs as connectors. Instead, the chip is given flat contacts or short pins. The result is mounted directly onto a PCB, which is designed with solder pads to match the contacts on the chip.

System availability

System availability quantifies the extent to which a system is available as required, when required. The concept applies to all systems, from IT systems to production systems to communications systems.

The simplicity of this availability metric – essentially, the percentage of required time during which the system is functioning as required – is in stark contrast to the complexity of managing service and maintenance. For example, the elevator system in a hotel must be available at all times. However, when there are multiple elevators, not all elevators need to be available during periods of low usage. So a rolling program of maintenance can maintain 100% availability even though it takes some elevators out of service at certain times.

System Average Interruption Duration Index (SAIDI)

SAIDI is the average number of hours of service interruption experienced by each customer in one year. Widely used by electricity distribution organizations, it is often used alongside System Average Interruption Frequency Index (SAIFI) to distinguish many short interruptions from a few longer interruptions.

The US Energy Information Administration collects SAIDI and SAIFI data for three categories of electricity distributor – municipals (owned by cities), co-ops (owned by members); and investor owned (owned by shareholders). In 2016, municipals’ customers experienced the lowest SAIDI and SAIFI of the three categories.

System on Chip


SOC is a type of integrated circuit where all of the components of a system (such as a computer) have been combined on a single chip. This may include distinct functions and technologies such as analogue, digital and radio frequency circuitry.

Systems Integration


SI is the discipline of combining separate computer (and physical) systems to act as a single co-ordinated whole. In Aerospace and Automotive, for example, OEMs are called systems integrators because their expertise is less and less in research and development (R&D), and more in assembling pre-built supplier systems using highly efficient manufacturing processes in their own factories.