Electronics manufacturing services (EMS) is a term used for companies that design, manufacture, test, distribute, and provide return/repair services for
electronic component
An electronic component is any basic discrete electronic device or physical entity part of an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singula ...
s and assemblies for
original equipment manufacturers (OEMs). The concept is also referred to as electronics contract manufacturing (ECM).
Many high-volume consumer electronic products have been built in China and countries of Southeast Asia, due to the speed of manufacture of high-volume low-cost electronics in those locations, as opposed to the United States.
Cities such as
Shenzhen
Shenzhen is a prefecture-level city in the province of Guangdong, China. A Special economic zones of China, special economic zone, it is located on the east bank of the Pearl River (China), Pearl River estuary on the central coast of Guangdong ...
, China and
Penang, Malaysia have become important production centres for the industry, attracting many consumer electronics companies such as
Apple Inc. Some companies such as
Flex and
Wistron are
original design manufacturers and providers of electronics manufacturing services.
History
The EMS industry was initially established in 1961 by
SCI Systems of Huntsville Alabama. The industry realized its most significant growth in the 1980s; at the time, most electronics manufacturing for large-scale product runs was handled by the OEMs in-house assembly. These new companies offered flexibility and eased
human resources
Human resources (HR) is the set of people who make up the workforce of an organization, business sector, industry, or economy. A narrower concept is human capital, the knowledge and skills which the individuals command. Similar terms include ' ...
issues for smaller companies doing limited runs. The
business model
A business model describes how a Company, business organization creates, delivers, and captures value creation, value,''Business Model Generation'', Alexander Osterwalder, Yves Pigneur, Alan Smith, and 470 practitioners from 45 countries, self-pub ...
for the EMS industry is to specialize in large
economies of scale
In microeconomics, economies of scale are the cost advantages that enterprises obtain due to their scale of operation, and are typically measured by the amount of Productivity, output produced per unit of cost (production cost). A decrease in ...
in manufacturing, raw materials
procurement
Procurement is the process of locating and agreeing to terms and purchasing goods, services, or other works from an external source, often with the use of a tendering or competitive bidding process. The term may also refer to a contractual ...
and pooling together resources, industrial design expertise as well as create added value services such as warranty and repairs. This frees up the customer who does not need to manufacture and keep huge inventories of products. Therefore, they can respond to sudden spikes in demand more quickly and efficiently.
The development of
surface mount technology (SMT) on
printed circuit board
A printed circuit board (PCB), also called printed wiring board (PWB), is a Lamination, laminated sandwich structure of electrical conduction, conductive and Insulator (electricity), insulating layers, each with a pattern of traces, planes ...
s (PCB) allowed for the rapid assembly of electronics. By the mid-1990s the advantages of the EMS concept became compelling and OEMs began outsourcing PCB assembly (PCBA) on a large scale. By the end of the 1990s and early 2000s, many OEMs sold their assembly plants to EMSs, aggressively vying for market share. A wave of consolidation followed as the more cash-flush EMS firms were able to buy up quickly both existing plants as well as smaller EMS companies.
Market segments

The global market for Electronics Manufacturing Services (EMS) reached an estimated value of US$504.2 billion in 2023 and is projected to grow at a CAGR of 4.94% during the forecast period 2024-2030, reaching a revised size of US$707.5 billion by 2030.
The EMS industry is commonly divided into Tiers by their revenue:
*Tier 1: >$5 Billion
*Tier 2: $500M to $5B
*Tier 3: $100M to $500M
*Tier 4: <$100M
There is no hard rule on the actual revenue designation at this time.
Other categories have been suggested by StepBeyond/EMSinsider and CIRCUITS ASSEMBLY: Micro Tier (<$50M); Tier 4 <10m and "Tier Mega" referring to the Big 2, Foxconn and Flex.
Another distinction is drawn between EMS that specializes in High Mix Low Volume (HMLV) and High Volume Low Mix (HVLM). Mix refers generally to the complexity or different models of the PCB assembly. Volume refers to the number of units built, with products like consumer electronics on the high end and prototype, medical electronics or machinery on the low end. Typically, lower Tier EMS provide HMLV and higher Tier provide HVLM.
During technology's late-1990s heyday, EMS players routinely acquired assets in high-cost locations. EMS players largely focused on
printed circuit board fabrication, leaving system assembly to the
OEMs. EMS companies largely disdained industries outside the world of information processing (computers) and communications. In recent years, EMS players have shifted production to low-cost geographies; embraced non-traditional industries including
consumer electronics
Consumer electronics, also known as home electronics, are electronic devices intended for everyday household use. Consumer electronics include those used for entertainment, Communication, communications, and recreation. Historically, these prod ...
, industrial, medical and instrumentation; and added substantial
vertical capabilities, stretching from design and
ODM through system assembly, test, delivery and
logistics
Logistics is the part of supply chain management that deals with the efficient forward and reverse flow of goods, services, and related information from the point of origin to the Consumption (economics), point of consumption according to the ...
, warranty and repair,
network service
In computer networking, a network service is an application running at the network layer and above, that provides data storage, manipulation, presentation, communication or other capability which is often implemented using a client–server or pe ...
s, software and silicon design, and customer service.
EMS has also started to provide design services used in conceptual product development advice and mechanical, electrical and software design assistance. Testing services perform in-circuit, functional, environmental, agency compliance, and analytical laboratory testing. Electronics manufacturing services are located throughout the world and provide numerous benefits. They vary in terms of production capabilities and comply with various quality standards and regulatory requirements.
E2MS
E
2MS (Electronic Engineering Manufacturing Service) refers to the strategy of integrating product development, prototyping and industrialization services into a traditional EMS business, with the aim to harness potential synergies. A typical E
2MS offering will start in the design phase, then continue to support the client in development, prototyping, tooling and production all the way to the testing phase, allowing for faster ramp-up as the product is prepared for mass-production up-front.
The term E
2MS was first coined by Escatec and has since been adopted by numerous Tier 2 and Tier 3 producers.
Larger companies (Tier 1) have gone even further and offered full concept to mass-production and often taking a stake in the intellectual property, becoming more similar to
ODM companies.
References
{{Major OEMs
Electronics manufacturing