Simplified Technical English: how to improve the translation of technical documents

In a maintenance manual, installation instructions or a safety procedure, an ambiguous sentence can lead to misunderstanding. It can delay an operation, increase the number of requests for clarification or result in misinterpretation. When the document is subsequently translated, every inaccuracy in the source version is carried over into all the target languages.

Understanding how Simplified Technical English improves the translation of technical documents therefore begins with examining the quality of the source text before translation. This controlled language governs vocabulary, grammar and sentence structure in order to produce clearer and more consistent content. It thus facilitates the work of writers, translators, reviewers and, above all, end users.

What is Simplified Technical English?

Simplified Technical English is a controlled language originally developed for aircraft maintenance documentation. Its aim is not to simplify technical content, but to limit wording that could be interpreted in different ways. The ASD-STE100 standard combines writing rules with a dictionary of approved words.

The ninth edition, published on 15 January 2025, contains 53 rules and approximately 900 approved words. Wherever possible, each general word is assigned a single meaning and a single grammatical category. However, companies can retain the technical nouns and verbs specific to their products, processes or industry.

This approach explains why STE is more than just a simplified form of English. It is a structured, documented and verifiable method. An overview of the rules of Simplified Technical English provides an understanding of its key principles, while the official ASD-STE100 website provides the standard’s rules and dictionary.

How Simplified Technical English improves the translation of technical documents

The first improvement takes place before translation. A source text written in STE contains fewer unnecessary synonyms, fewer pronouns with ambiguous references and fewer complex sentence structures. The translator therefore has fewer ambiguities to resolve and can devote more time to technical accuracy.

The second improvement relates to consistency. When the same action, part or state is always referred to in the same way, translation memories find more reliable matches. Recurring segments are easier to reuse, glossaries are easier to maintain and discrepancies between versions are reduced.

The STE rules with the greatest impact on translation

STE recommends using approved words in their intended sense, avoiding overly long noun phrases, favouring the active voice and writing short sentences. It also recommends limiting each sentence to a single instruction and each paragraph to a single subject.

Take the following wording, for example: “After completion of the pressure check, removal of the protective cover should be carried out.” It contains a nominalisation, a passive voice and an indirect description of the action. A version more in line with STE would be: “Complete the pressure check. Then remove the protective cover.” The translator can immediately identify the two actions, their order of execution and the person responsible for carrying them out.

These rules reduce several common difficulties:

• polysemous words whose meaning changes depending on the context;
• pronouns such as “it” or “they” with an unclear antecedent;
• long strings of nouns that are difficult to break down;
• sentences that combine a condition, an action and a result;
• terminological variants used to refer to the same component.

Better quality at every stage of the translation workflow

STE first and foremost improves the quality of the source text. This improvement is essential because an accurate translation cannot fully compensate for a poorly structured instruction. As indicated in our article on writing and translating technical documentation, translation quality also depends on the rigour of the source document, particularly the use of consistent terminology and clearly defined writing rules.

A writer trained in STE makes the links between actions, objects and conditions clearer. University training courses on STE also emphasise the production of clear, unambiguous documentation for non-native English readers.

During translation, a controlled text integrates more effectively with computer-assisted translation tools. Translation memories recognise recurring segments more easily, while terminology databases flag variations in vocabulary. Machine translation can also produce more predictable results when source sentences are consistent, although specialised human review is still necessary for sensitive content.

The final stage is validation. The linguistic reviewer can focus on consistency and readability, while the subject-matter expert checks technical compliance. For documentation intended for multiple markets, a professional translation process coordinated with the drafting of the source document helps avoid dealing separately with problems that have the same underlying cause.

Terminology, translation memories and reduced rework

In an uncontrolled technical corpus, the same component may be referred to as “cover”, “panel”, “lid” or “protection”, depending on the author. Although these terms may seem similar, they are not necessarily interchangeable. STE imposes lexical discipline that requires the company to distinguish between genuine synonyms and terms with a specific function.

These benefits are particularly noticeable in the technical translation of large manuals that are regularly updated. They are also evident in the translation of instructions for use, where concise wording must remain accurate despite layout, safety and compliance constraints.

The limitations of STE

STE does not replace technical expertise. A sentence may comply with all the linguistic rules and still be technically incorrect. The document must always be validated by someone who is familiar with the product, the risks, the applicable standards and industry practices.

Nor does it replace a terminology strategy. The ASD-STE100 dictionary governs general vocabulary, but each company must define its component names, technical verbs, abbreviations and naming conventions. Without this governance, industry-specific terminology inconsistencies can reappear in the documentation.

A marketing document, scientific report or legal text may require a different style. Even in technical documentation, it is important to decide whether to apply ASD-STE100 strictly or to create a controlled writing guide based on its principles.

How to implement STE in a multilingual project

Implementation begins with an audit. This audit helps identify overly long sentences, synonyms, ambiguities, terminology variations and content that is frequently retranslated.

The company can launch a pilot project on a high-priority or high-impact document, such as a maintenance procedure, installation guide or safety instructions. The process should include the following steps:

1. define the scope and level of application of STE;
2. compile, review or harmonise specialised terminology;
3. train writers and reviewers;
4. integrate the rules into templates and writing tools;
5. translate a pilot corpus and measure discrepancies;
6. adapt the guide before wider deployment.

In particular, it is possible to track the number of clarification requests sent to writers, terminology corrections, inconsistencies detected during review and reused segments, as well as the time spent on updates.

In which industries is STE most useful?

In the aerospace sector, the ASD-STE100 website illustrates its use in analysing and writing maintenance documentation. The Université libre de Bruxelles also presents STE as a standardised language designed to make technical documentation clear and unambiguous.

However, its principles are useful across many industries: industrial machinery, energy, transport, medical devices, electronics, software, laboratory equipment and after-sales services. The use of a controlled language is particularly beneficial when instructions are repetitive, translated into several languages, essential to safety or regularly updated.

Richard Ryan’s work on controlled languages shows that they can help translators produce technical documents that are more readable, consistent and user-friendly. By governing vocabulary and sentence structure, they help to improve both translation productivity and the usability of the final document.

Conclusion: improving translation starts with improving the source

Simplified Technical English improves the translation of technical documents because it addresses the causes of errors before they are carried over into the target languages. It reduces ambiguity, stabilises terminology, simplifies the structure of instructions and makes checks more systematic.

Its adoption should not be regarded as the simple application of a set of linguistic rules. Its implementation requires collaboration between the teams responsible for writing, engineering, terminology, translation and content management.