What is  ISO/IEC/IEEE 29119‑4 about? 
ISO/IEC/IEEE 29119‑4 is the fourth part of a series of documents applicable for software testing. ISO/IEC/IEEE 29119‑4 defines test design techniques that can be used during the test design and implementation process that is defined in ISO/IEC/IEEE 291192.
Each technique follows the test design and implementation process that is defined in ISO/IEC/IEEE 291192. BS ISO/IEC/IEEE 29119‑4 is intended for, but not limited to, testers, test managers, and developers, particularly those responsible for managing and implementing software testing.
Note: ISO/IEC/IEEE 29119‑4 does not describe a process for test design and implementation. The intent is to describe a series of techniques that have wide acceptance in the software testing industry.
Who is BS ISO/IEC/IEEE 29119‑4 for? 
BS ISO/IEC/IEEE 29119‑4 on software testing is useful for: 
- Software developers
- Software testers
- Stakeholders
- Quality assurance testers
Why should you use  ISO/IEC/IEEE 29119‑4?
A test model represents testable aspects of a test item, such as a function, transaction, feature, quality attribute, or structural element identified as a basis for testing. The test model reflects the required test completion criterion in the test strategy.
The purpose of ISO/IEC/IEEE 29119‑4 is to provide an International Standard that defines software test design techniques (also known as test case design techniques or test methods) that can be used within the test design and implementation process that is defined in ISO/IEC/IEEE 291192. 
The test design techniques presented in ISO/IEC/IEEE 29119‑4 can be used to derive test cases that, when executed, generate evidence that test item requirements have been met or that defects are present in a test item (i.e. that requirements have not been met). Risk-based testing can be used to determine the set of techniques that are applicable in specific situations.
What’s changed since the last update? 
ISO/IEC/IEEE 291194:2021 supersedes ISO/IEC/IEEE 291194:2015, which is withdrawn. The main changes compared to the previous edition are as follows:
- The test techniques in ISO/IEC/IEEE 291194 are defined using a new form of the test design and implementation process from ISO/IEC/IEEE 291192. In BS ISO/IEC/IEEE 291194:2015, this process was based on the use of test conditions. Feedback on the use of the previous edition highlighted a problem with users’ understanding of test conditions and their use for deriving test cases
- ISO/IEC/IEEE 291194:2021 has replaced the use of test conditions with test models. It provides more detail on this change and the introduction describes the new process
