Application of Systems Engineering Standards
Lead Authors: Garry Roedler Contributing Authors: William Bearden, David Endler, Mike Yokell
Standards can have an influence on organizations and their projects as indicated in Figure 1 (below). The standards provide sets of process, project, and product requirements and associated guidance that organizations use to influence the definition of their organization and project specific processes. Some pitfalls and good practices in utilizing standards are also identified in the article on Systems Engineering Related Standards Landscape. In this article, several additional factors related to the utilization of the standards in systems engineering (SE) are presented.
Standards and their Utilization
A standard is an agreed upon, repeatable way of doing something. It is a published document that contains a technical specification or other precise criteria designed to be used consistently as a rule, guideline, or definition. Standards help to make life simpler and to increase the reliability and the effectiveness of many goods and services we use, as detailed in Why Standards. Standards are created by bringing together the experience and expertise of relevant stakeholders, such as the producers, sellers, buyers, users, and regulators of a particular material, product, process, or service.
Standards are designed for voluntary use and do not impose any regulations. However, laws and regulations may address certain standards and may make compliance with them compulsory.
Further, organizations and their enterprises may choose to use standards as a means of providing uniformity in their operations and/or the products and services that they produce. The standard becomes a part of the corporate culture. In this regard, it is interesting to note that the ISO/IEC/15288 (2023) standard has provided such guidance and has provided a strong framework for systems engineers, as well as systems engineering and business management, as forecast earlier by Arnold and Lawson (2004).
ISO directives state the following:
A standard does not in itself impose any obligation upon anyone to follow it. However, such an obligation may be imposed, for example, by legislation or by a contract. In order to be able to claim compliance with a standard, the user (of the standard) needs to be able to identify the requirements he is obliged to satisfy. The user needs also to be able to distinguish these requirements from other provisions where a certain freedom of choice is possible. Clear rules for the use of verbal forms (including modal auxiliaries) are therefore essential.
Requirements, Recommendations, and Permissions
In order to provide specificity, standards employ verb forms that convey requirements, recommendations, and permissions. For example, the ISO directives specify the following verb usages:
- The word shall indicates requirements strictly to be followed in order to conform to the standard and from which no deviation is permitted.
- The word should indicates that among several possibilities, one is recommended as particularly suitable without mentioning or excluding others, or that a certain course of action is preferred, but not necessarily required, or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited.
- In the past, the word may indicates a course of action permissible within the limits of the standard. More recently, the use of may is not preferred for use in a standard and should be avoided. Can is the preferred term in most situations.
The directive also indicates that standards should avoid the use of will, must, and other imperatives. Futhermore, the use of the term ensure should be avoided, since it is rare that anything can be absolutely ensured. It reflects a guarantee. However, the phrase help ensure is acceptable.
Certification, Conformance, and Compliance
In the context of the management system standards (such as ISO 9001 or ISO 14000), certification refers to the issuing of written assurance (the certificate) by an independent external body that it has audited a management system and verified that it conforms to the requirements specified in the standard.
Typically, other more specific systems engineering standards are not the subject of certification. They are self-imposed in order to improve uniformity of organization and enterprise operations or to improve the quality of products and services. Alternatively, they may be dictated by legislation, policy, or as part of a formal agreement between an acquirer and a supplier.
In the context of engineering standards, compliance typically refers to adhering to mandatory legal or regulatory requirements, while conformance refers to adhering to voluntary standards or specifications. Compliance is often driven by external authorities, while conformance is often a company's internal commitment.
Conformance to standards is generally considered to be the voluntary action of an organization to meet the requirements or tailored requirements of a consensus standard or other guidance or specification. Many standards include a Conformance Clause that identifies what is required to make a claim of conformance or tailored conformance to the standard. This is especially true for engineering process standards.
Sometimes Conformance testing is a focus for product standards. Conformance testing, or type testing, is testing to determine whether a product or system meets some specified standard that has been developed for efficiency or interoperability. To aid in this, many test procedures and test setups have been developed either by the standard's maintainers or by external organizations, such as the Underwriters Laboratory (UL), specifically for testing conformity to standards.
Conformance testing is often performed by external organizations, which is sometimes the standards body itself, to give greater guarantees of compliance. Products tested in such a manner are then advertised as being certified by that external organization as complying with the standard. Service providers, equipment manufacturers, and equipment suppliers rely on this data to ensure quality of service (QoS) through this conformance process.
When compliance to a or more standards is needed, the agreement or contract has usually identified the standard(s) compliance as a requirement. Compliance with engineering standards is crucial for applications with a high need for safety, reliability, and functionality of products, systems, and infrastructure. It involves adhering to established rules, regulations, and best practices to meet industry requirements and legal obligations. Compliance is often enforced by external authorities, such as government agencies or industry bodies, and failure to comply can result in penalties or sanctions.
Key aspects of standards compliance include:
- Identifying and selecting the relevant standards that will be part of the agreement.
- Identifying and understand the applicable requirements of the standards.
- Integrating the requirements of the standards into the organization or project processes, product requirements, or project requirements with appropriate adaptation and tailoring; and documenting the incorporation and compliance demonstration needed.
- Verifying compliance through appropriate and valid means and documenting it.
Some challenges for compliance include:
- Keeping current – standards and other requirements can change, then requiring changes ot project planning and implementation, if a specific version is not part of the agreement.
- Balancing between compliance with standards and leveraging innovation in products or processes.
- Capturing and maintaining accurate documentation of the compliance can require structured and ongoing data management.
Tailoring of Standards
Since the SE standards provide guidelines, they are most often tailored to fit the needs of organizations and their enterprises in their operations and/or for the products and services that they provide, as well as to provide agreement in a contract. Tailoring is a process described in an annex to the ISO/IEC/IEEE 15288 (2023) standard. ISO/IEC/IEEE 15288 (2023) addresses the issues of conformance, compliance, and tailoring as follows:
- Full conformance, or a claim of full conformance, first declares the set of processes or other requirements for which conformance is claimed. Full conformance is achieved by demonstrating that all of the requirements have been satisfied using the outcomes or other criteria as evidence.
- Tailored conformance for processes uses the standard as a basis for establishing a set of processes and their requirements. However, the specific requirements are selected, excluded, or modified in accordance with the tailoring process. A clear statement is made regarding the scope of the claimed tailored conformance.
- The tailored text for which tailored conformance is claimed is declared. Tailored conformance is achieved by demonstrating that requirements for the processes, as tailored, have been satisfied using the outcomes as evidence.
- When the standard is used to help develop an agreement between an acquirer and a supplier, clauses of the standard can be selected for incorporation in the agreement with or without modification. In this case, it is more appropriate for the acquirer and supplier to claim compliance with the agreement than conformance with the standard, since the agreement usually becomes legally binding.
- Any organization (e.g., a national organization, industrial association, or company) imposing the standard as a condition of trade should specify and make public the minimum set of required processes, activities, and tasks which constitute a supplier's conformance with the standard.
Per ISO/IEC/IEEE 24748-2, “Life cycle models, as well as the processes from ISO/IEC/IEEE 15288, may be adapted for an individual project to reflect the variations appropriate to the organization, project and system while still being able to claim tailored conformance.”
ISO/IEC/IEEE 24748-2 provides an informational list of circumstances that influence tailoring.
References
Works Cited
Arnold, S., and H. Lawson. 2004. "Viewing systems from a business management perspective." Systems Engineering, 7 (3): 229.
ISO/IEC/IEEE. 2023. Systems and Software Engineering -- System Life Cycle Processes. Geneva, Switzerland: International Organisation for Standardisation / International Electrotechnical Commissions / Institute of Electrical and Electronics Engineers. ISO/IEC/IEEE 15288:2023.
Roedler, G. 2010. "An Overview of ISO/IEC/IEEE 15288, System Life Cycle Processes. Asian Pacific Council on Systems Engineering." Asia-Pacific Council on Systems Engineering (APCOSE) Conference, Keelung, Taiwan.
Roedler, G. 2011. "Towards Integrated Systems and Software Engineering Standards." National Defense Industrial Association (NDIA) Conference, San Diego, CA, USA.
Primary References
Roedler, G. 2010. "An Overview of ISO/IEC/IEEE 15288, System Life Cycle Processes." Proceedings of the 4th Asian Pacific Council on Systems Engineering (APCOSE) Conference, 4-6 October 2010, Keelung, Taiwan.
ISO. 2015. Quality management systems -- Requirements. Geneva, Switzerland: International Organisation for Standardisation. ISO 9001:2015.
ISO. 2015. Environmental management systems -- Requirements with guidance for use. Geneva, Switzerland: International Organisation for Standardisation. ISO 14000:2015
ISO/IEC/IEEE. 2023. Systems and Software Engineering -- System Life Cycle Processes. Geneva, Switzerland: International Organisation for Standardisation / International Electrotechnical Commissions / Institute of Electrical and Electronics Engineers. ISO/IEC/IEEE 15288: 2023.
ISO/IEC/IEEE. 2024. "Systems and Software Engineering -- Life Cycle Management – Part 1: Guidelines for life cycle management,". Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC)/ Institute of Electrical and Electronics Engineers (IEEE). ISO/IEC/IEEE 24748-1:2024.
ISO/IEC/IEEE. 2024. Systems and Software Engineering -- Life Cycle Management – Part 2: Guidelines for the application of ISO/IEC/IEEE 15288 (system life cycle processes). Geneva, Switzerland: International Organisation for Standardisation / International Electrotechnical Commissions / Institute of Electrical and Electronics Engineers. ISO/IEC/IEEE 24748-2:2024.
INCOSE. 2023. INCOSE Systems Engineering Handbook 5th Edition. International Council on Systems Engineering. Hoboken, NJ, USA: John Wiley & Sons. INCOSE SE Handbook.
Additional References
None.