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− | [[Stakeholder Requirement (glossary)|Stakeholder needs and requirements]] represent the views of those at the business or enterprise operations level—that is, of [[User (glossary)|users]], [[Acquirer (glossary)|acquirers]], [[Customer (glossary)|customers]], and other [[Stakeholder (glossary)|stakeholders]] as they relate to the problem (or opportunity), as a set of requirements for a solution that can provide the services needed by the stakeholders in a defined environment. Using enterprise-level [[Concept of Operations (ConOps) (glossary)]] and the system-level life cycle concepts (see [[Business or Mission Analysis]] for details) as guidance, stakeholders from business operations are led through a structured process to elicit stakeholder needs (in the form of a refined system-level OpsCon and other life-cycle concepts). Stakeholder needs are then transformed into a defined set of Stakeholder Requirements that often are documented in a Stakeholder Requirement Specification, which may be in the form of a model, a document containing textual requirement statements or both.
| + | {{Term|Concept (glossary)|Concept}} Definition is the set of systems engineering (SE) activities in which the problem space and the needs and requirements of the business or enterprise and {{Term|Stakeholder (glossary)|stakeholders}} are closely examined. The activities are grouped and described as generic processes which include Mission Analysis and Stakeholder Needs and Requirements. Concept Definition begins before any formal definition of the {{Term|System-of-Interest (glossary)|system-of-interest}} (SoI) is developed. |
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− | Stakeholder requirements play major roles in systems engineering, as they:
| + | {{Term|Mission Analysis (glossary)|Mission Analysis}} focuses on the needs and requirements of business or enterprise — that is, on defining the problem or opportunity that exists (in what is often called the problem space or problem situation), as well as understanding the constraints on and boundaries of the selected system when it is fielded (in what is often called the solution space). The {{Term|Stakeholder Requirement (glossary)|Stakeholder Needs and Requirements}} process explores and defines the operational aspects of a potential solution for the stakeholders from their point of view, independent of any specific solution. In these two Concept Definition activities, business or enterprise decision makers and other stakeholders describe ''what'' a solution should accomplish and ''why'' it is needed. Both ''why'' and ''what'' need to be answered before consideration is given to ''how'' the problem will be addressed (i.e., what type of solution will be implemented) and ''how'' the solution will be defined and developed. |
− | * Form the basis of [[System Requirement (glossary)|system requirements]] activities.
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− | * Form the basis of system [[Validation (glossary)|validation]] and stakeholder acceptance .
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− | * Act as a reference for [[Integration (glossary) | integration]] and [[Verification (glossary)|verification]] activities.
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− | * Serve as means of communication between the technical staff, management, finance department, and the stakeholder community.
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− | This topic describes the definition of stakeholder needs and requirements which involves the activities necessary to elicit and prioritize the needs of the stakeholder(s), and transform those needs into a set of defined stakeholder requirements. Defining the problem or the issue to be solved, identifying the opportunity for developing a new solution, or improving a [[System-of-Interest (glossary)|system-of-interest (SoI)]] must begin prior to starting the activities necessary to define stakeholder needs and requirements. This means that an initial context of use of the new or modified mission, operation, or capability has already been characterized (see [[Business or Mission Analysis]]). System requirements are considered in detail during [[System Definition (glossary) | system definition]]. None of the above can be considered complete until consistency between the two has been achieved, as demonstrated by [[Traceability (glossary)|traceability]], for which a number of iterations may be needed.
| + | If a new or modified system is needed, then {{Term|System Definition (glossary)|System Definition}} activities are performed to assess the system. See [[Life Cycle Processes and Enterprise Need]] for further detail on the transformation of needs and requirements from the business or enterprise and stakeholder levels of abstraction addressed in Concept Definition to the system and system element level of abstraction addressed in System Definition. |
− | ==Purpose and Definition==
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− | The purpose of the Stakeholder Needs and Requirements definition activities are to elicit a set of clear and concise needs related to a new or changed mission for an enterprise (see [[Business or Mission Analysis|mission analysis]] (MA) for information relevant to identifying and defining the mission or operation), and to transform these stakeholder needs into verifiable stakeholder requirements.
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− |
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− | Stakeholders may well begin with desires, and expectations that may contain vague, ambiguous statements that are difficult to use for SE activities. Care must be taken to ensure that those desires and expectations are coalesced into a set of clear and concise need statements that are useful as a start point for system definition. These need statements will then need to be further clarified and translated into more ''engineering-oriented'' language in a set of stakeholder requirements to enable proper architecture definition and requirement activities. As an example, a need or an expectation such as, ''to easily ''manoeuvre ''a car in order to park'', will be transformed in a set of [[Stakeholder Requirement (glossary)|stakeholder requirements]] to a statement such as, ''increase the driviability of the car'', ''decrease the effort for handling'', ''assist the piloting'', ''protect the coachwork against shocks or scratch'', etc.
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− | To allow a clear description of the activities of stakeholder needs and requirements to be described a generic view of the business teams and roles involved in a typical enterprise has been used below, this includes teams such a business management and business operations; and roles including requirements engineer and business analyst. For an overview of these roles and how they enable both stakeholder and business requirements across the layers of a typical enterprise see [[Life Cycle Processes and Enterprise Need]].
| + | The specific activities and sequence of Concept Definition activities and their involvement with the life cycle activities of any system, and in particular the close integration with System Definition activities, will be dependent upon the type of {{Term|Life Cycle Model (glossary)|life cycle model}} being utilized. See [[Applying Life Cycle Processes]] for further discussion of the concurrent, iterative and recursive nature of these relationships. |
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− | ==Principles and Concepts== | + | ==Topics== |
| + | Each part of the SEBoK is divided into knowledge areas (KAs), which are groupings of information with a related theme. The KAs in turn are divided into topics. This KA contains the following topics: |
| + | *[[Business or Mission Analysis]] |
| + | *[[Stakeholder Needs and Requirements]] |
| + | See the article [[Matrix of Implementation Examples]] for a mapping of case studies and vignettes included in Part 7 as well as topics covered in Part 3. |
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− | ===Identifying Stakeholders=== | + | ==Concept Definition Activities== |
− | Stakeholders of a SoI may vary throughout the [[Life Cycle (glossary)|life cycle]]. Thus, in order to get a complete set of needs and subsequent requirements, it is important to consider all stages of the [[Life Cycle Model (glossary)|life cycle model]] when identifying the stakeholders or classes of stakeholders.
| + | There are two primary activities discussed under concept definition: {{Term|Mission Analysis (glossary)|Mission Analysis}} and the definition of {{Term|Stakeholder Requirement (glossary)|Stakeholder Needs and Requirements}}: |
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− | Every system has its own stages of life, which typically include stages such as concept, development, production, operations, sustainment, and retirement (for more information, please see [[Life Cycle Models]]). For each stage, a list of all stakeholders having an interest in the future system must be identified. The goal is to get every stakeholder’s point of view for every stage of the system life in order to consolidate a complete set of stakeholder needs that can be prioritized and transformed into the set of stakeholder requirements as exhaustively as possible. Examples of stakeholders are provided in Table 1.
| + | # [[Business or Mission Analysis|Mission Analysis]] begins an iteration of the life cycle of a potential SoI that could solve a problem or realize an opportunity for developing a new product, service, or enterprise. These activities assist business or enterprise decision makers to define the problem space, identify the stakeholders, develop preliminary operational concepts, and distinguish environmental conditions and constraints that bound the solution space. In other words, mission analysis takes the enterprise capability gap or opportunity and defines the problem/opportunity in a manner that provides a common understanding encapsulated in what are referred to as “business or mission needs.” Business or mission needs are then used to produce a clear, concise, and verifiable set of business requirements. |
− | {|
| + | #The [[Stakeholder Needs and Requirements]] activity works with stakeholders across the life cycle to elicit and capture a set of needs, expectations, goals, or objectives for a desired solution to the problem or opportunity, referred to as "stakeholder needs". The stakeholder needs are used to produce a clear, concise, and verifiable set of stakeholder requirements. Stakeholder needs and requirements identify and define the needs and requirements of the stakeholders in a manner that enables the characterization of the solution alternatives. |
− | |+'''Table 1. Stakeholder Identification Based on Life Cycle Stages.''' (SEBoK Original)
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− | !Life Cycle Stage
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− | !Example of Related Stakeholders
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− | |-
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− | |Engineering
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− | |Acquirer, panel of potential users, marketing division, research and development department, standardization body, suppliers, verification and validation team, production system, regulator/certification authorities, etc.
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− | |-
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− | |Development
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− | |Acquirer, suppliers (technical domains for components realization), design engineers, integration team, etc.
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− | |-
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− | |Transfer for Production or for Use
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− | |Quality control, production system, operators, etc.
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− | |-
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− | |Logistics and Maintenance
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− | |Supply chain, support services, trainers, etc.
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− | |-
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− | |Operation
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− | |Normal users, unexpected users, etc.
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− | |-
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− | |Disposal
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− | |Operators, certifying body, etc.
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− | |}
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− | === '''Identifying Stakeholder Needs''' ===
| + | Mission Analysis takes the business and stakeholders' needs and requirements and carries the analysis down from problem space to solution space, including concept, mission, and boundary or context so that a solution concept (at the black-box level) can be selected from the alternatives. Figure 1 in the [[Business or Mission Analysis|Mission Analysis]] topic depicts this interaction. The products and artifacts produced during Concept Definition are then used in {{Term|System Definition (glossary)|System Definition}}. |
− | Once business management is satisfied that their needs and requirements are reasonably complete, they pass them on to the business operations team. Here, the Stakeholder Needs and Requirements (SNR) Definition Process uses the ConOps, or Strategic Business Plan (SBP), and the life-cycle concepts as guidance. The requirements engineer (RE) or business analyst (BA) leads stakeholders from the business operations layer through a structured process to elicit stakeholder needs—in the form of a refined OpsCon (or similar document) and other life-cycle concepts. The RE or BA may use a a fully or partially structured process to elicit specific needs, as described in models such as user stories, use cases, scenarios, system concepts, and operational concepts.
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− | === '''Identifying Stakeholder Requirements''' ===
| + | The different aspects of how {{Term|Systems Thinking (glossary)|systems thinking}} is applicable to concept definition are discussed in SEBoK Part 2. In particular, the use of a combination of {{Term|Hard System (glossary)|hard system}} and {{Term|Soft System (glossary)|soft system}} approaches depending on the type of problem or class of solution is discussed in [[Identifying and Understanding Problems and Opportunities]] and the contrast between top-down and bottom-up approaches in [[Synthesizing Possible Solutions]]. |
− | Stakeholder needs are transformed into a formal set of stakeholder requirements, which are captured as models or documented as textual requirements in and output typically called a Stakeholder Requirement Specification (StRS), Stakeholder Requirement Document (StRD) or similar. That transformation should be guided by a well‐defined, repeatable, rigorous, and documented process of requirements analysis. This requirements analysis may involve the use of functional flow diagrams, timeline analysis, N2 Diagrams, design reference missions, modeling and simulations, movies, pictures, states and modes analysis, fault tree analysis, failure modes and effects analysis, and trade studies.
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− | === '''Collecting Stakeholder Needs and Requirements''' === | + | ==Drivers of Solution on Problem Definition: Push Versus Pull== |
− | There are many ways to collect stakeholder needs and requirements. It is recommended that several techniques or methods be considered during elicitation activities to better accommodate the diverse set of sources, including:
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− | * Structured brainstorming workshops
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− | * Interviews and questionnaires
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− | * Technical, operational, and/or strategy documentation review
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− | * Simulations and visualizations
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− | * Prototyping
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− | * Modeling
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− | * Feedback from [[System Verification|verification]] and [[System Validation|validation]] processes,
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− | * Review of the outcomes from the [[System Analysis|system analysis]] process (ISO/IEC 2015)
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− | * Quality function deployment (QFD) - can be used during the needs analysis and is a technique for deploying the "voice of the customer”. It provides a fast way to translate customer needs into requirements. (Hauser and Clausing 1988)
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− | * Use case diagrams (OMG 2010)
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− | * Activity diagrams (OMG 2010)
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− | * Functional flow block diagrams
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− | === From the Capture of Stakeholder Needs to the Definition of Stakeholder Requirements ===
| + | Problem definition and solution design depend on each other. Solutions should be developed to respond appropriately to well-defined problems. Problem definitions should be constrained to what is feasible in the solution space. {{Term|System Analysis (glossary)|System Analysis}} activities are used to provide the link between problems and solutions. |
− | Several steps are necessary to understand the maturity of stakeholder needs and to understand how to improve upon that maturity. Figure 1 presents the ''cycle of needs ''as it can be deduced from Professor Shoji Shiba's and Professor Noriaki Kano's works and courses, and is adapted here for systems engineering (SE) purposes.
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− | [[File:SEBoKv05_KA-SystDef_Cycle_of_needs.png|centre|thumb|600x600px|
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− | '''Figure 1. Cycle of Needs (Faisandier 2012).''' Permission granted by Sinergy'Com. All other rights are reserved by the copyright owner.
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− | ]]
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− | Figure 1 shows the steps and the position of the stakeholder requirements and system requirements in the engineering cycle. Below are explanations of each stage of requirements (Faisandier 2012); to illustrate this, consider this example of a system related to infectious disease identification:
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− | * '''Real needs '''are those that lie behind any perceived needs (see below); they are conditioned by the context in which people live. As an example, a generic need could be the ability to ''identify infectious diseases easily.''Often, real needs appear to be simple tasks.
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− | * '''Perceived needs '''are based on a person’s awareness that something is wrong, that something is lacking, that improvements could be made, or that there are business, investment, or market opportunities that are not being capitalized upon. Perceived needs are often presented as a list of organized expectations resulting from an analysis of the usage conditions for the considered action (see [[Business or Mission Analysis]]). Following from the infectious disease example above, the real need might be perceived as a need to ''carry out medical tests in particular circumstances (laboratories, points of care, hospitals, and/or human dispensaries). ''Since the real need is seldom clearly expressed, richness of the knowledge of the perceived needs is used as a basis for potential solutions. This step has to be as complete as possible to cover all the contexts of use.
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− | * '''Expressed needs '''originate from perceived needs in the form of generic actions or constraints, and are typically prioritized. In the example, if safety is the primary concern, the expressed need to ''protect the operator against contamination ''may take priority over other expressed needs such as ''assist in the execution of tests. ''When determining the expressed needs, the analysis of the expected mission or services in terms of operational scenarios takes place.
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− | * '''Retained needs '''are selected from the expressed needs. The selection process uses the prioritization of expressed needs to achieve a solution or to make attaining solutions feasible. The retained needs allow the consideration of potential solutions for a SoI. These retained ''stakeholder intentions do not serve as stakeholder requirements, since they often lack definition, analysis, and possibly consistency and feasibility. Using the concept of operations to aid the understanding of the stakeholder intentions at the organizational level and the system operational concept from the system perspective, requirements engineering leads stakeholders from those initial intentions to structured and more formal stakeholder requirement statements, ''ISO/IEC/IEEE 29148 ''Systems and software engineering - Requirements engineering '' (ISO 2011). Characteristics of good requirements can be found in (ISO 2011). Exploration of potential solutions must start from this step. The various solutions suggested at this step are not yet products, but describe means of satisfying the stakeholder requirements. Each potential solution imposes constraints on the potential future SoI.
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− | * '''Specified needs''', are the translation of the stakeholder needs to represent the views of the supplier, keeping in mind the potential, preferred, and feasible solutions. Specified needs are translated into system requirements. Consistent practice has shown this process requires [[Iteration (glossary)|iterative]] and [[Recursion (glossary)|recursive]] steps in parallel with other life cycle processes through the system design hierarchy (ISO 2011).
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− | * '''Realized needs '''are the product, service, or enterprise realized, taking into account every specified need (and hence, the retained needs).
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− | Each class of needs listed above aligns with an area of the SE process. For example, the development of ''specified needs ''requirements is discussed in the [[System Requirements]] topic. For more information on how requirements are used in the systems engineering process, please see the [[System Definition]] knowledge area (KA).
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− | ===Classification of Stakeholder Requirements===
| + | There are two paradigms that drive the ways in which concept definition is done: ''push'' and ''pull''. The ''pull'' paradigm is based on providing a solution to an identified problem or gap, such as a missing mission capability for defense or infrastructure. The ''push'' paradigm is based on creating a solution to address a perceived opportunity, such as the emergence of an anticipated product or service that is attractive to some portion of the population (i.e. whether a current market exists or not). This can impact other life cycle processes, such as in verification and validation, or alpha/beta testing as done in some commercial domains. |
− | Several classifications of stakeholder requirements are possible, e.g. ISO/IEC 29148, section 9.4.2.3 (ISO 2011) provides a useful set of elements for classification. Examples of classification of stakeholder requirements include: service or functional, operational, interface, environmental, human factors, logistical, maintenance, design, production, verification requirements, validation, deployment, training, certification, retirement, regulatory, environmental, reliability, availability, maintainability, design, usability, quality, safety, and security requirements. Stakeholders will also be faced with a number of constraints, including: enterprise, business, project, design, realization, and process constraints.
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− | ==Process Approach==
| + | As systems generally integrate existing and new {{Term|System Element (glossary)|system elements}} in a mixture of push and pull, it is often best to combine a bottom-up approach with a top-down approach to take into account legacy elements, as well as to identify the services and capabilities that must be provided in order to define applicable interface requirements and constraints. This is discussed in [[Applying Life Cycle Processes]]. |
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− | ===Activities of the Process=== | + | ==References== |
− | Major activities and tasks performed during this process include the following:
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− | * Identify the stakeholders or classes of stakeholders across the life cycle.
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− | * Elicit, capture, or consolidate the stakeholder needs, expectations, and objectives as well as any constraints coming from the mission and business analysis processes.
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− | *Refine the OpsCon and other life-cycle concepts (acquisition concept, deployment concept, support concept, and retirement concept).
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− | *Prioritize the stakeholder needs.
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− | *Transform the prioritized and retained stakeholder needs into stakeholder requirements.
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− | * Verify the quality of each stakeholder requirement and of the set of stakeholder requirements using the characteristics of good requirements identified in the [[System Requirements]] article.
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− | * Validate the content and the relevance of each stakeholder requirement with corresponding stakeholder representatives providing [[Rationale (glossary)|rationale (glossary)]] for the existence of the requirement.
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− | * Identify potential [[Risk (glossary) |risks]] (or threats and hazards) that could be generated by the stakeholder requirements (for further information, see [[Risk Management]]).
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− | * Synthesize, record, and manage the stakeholder requirements and potential associated risks.
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− | | |
− | ===Artifacts, Methods and Modeling Techniques===
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− | | |
− | This process may create several artifacts, such as:
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− | * Recommendations to refine the Business Requirement Specification (if necessary)
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− | * Refined life-cycle concepts (OpsCon, acquisition concept, deployment concept, support concept, and retirement concept)
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− | * Stakeholder requirements (in the form of a model or a document containing textual requirements, such as the Stakeholder Requirement Specification)
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− | * Stakeholder interview reports
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− | * Stakeholder requirements database
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− | * Stakeholder requirements justification documents (for traceability purposes)
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− | * Input for draft verification and validation plans
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− | | |
− | The content, format, layout and ownership of these artifacts will vary depending on who is creating them and in which domains they will be used. Between these artifacts and the outputs of the process, activities should cover the information identified in the first part of this article.
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− | | |
− | ==Practical Considerations==
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− | Major pitfalls encountered with stakeholder requirements are presented in Table 3.
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− | | |
− | <center>
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− | {|
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− | |+'''Table 3. Major Pitfalls for Stakeholder Requirements.''' (SEBoK Original)
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− | !Pitfall
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− | !Description
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− | |-
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− | |'''Operator Role Not Considered'''
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− | |Sometimes engineers do not take into account the humans acting as operators inside a system or those who use the system and are outside of the system. As a consequence, elements are forgotten (e.g. roles of operators).
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− | |-
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− | |'''Exchanges with External Objects Forgotten'''
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− | |The exhaustiveness of requirements can be an issue; in particular, the interfaces with external objects of the context of the system can be forgotten (exchanges of matter, energy, information).
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− | |-
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− | |'''Physical Connections with External Objects Forgotten'''
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− | |Within the interface issue, physical connections of the system-of-interest with external objects can be forgotten (technological constraints).
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− | |-
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− | |'''Forgotten Stakeholders'''
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− | |Stakeholders can be forgotten, as everyone thinks of direct users, customers, and suppliers; however, one may fail to consider those who do not want the system to exist and malevolent persons.
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− | |}
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− | </center>
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− | | |
− | | |
− | Proven practices with stakeholder requirements are presented in Table 4.
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− | | |
− | <center>
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− | {|
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− | |+'''Table 4. Stakeholder Requirements Proven Practices.''' (SEBoK Original)
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− | !Practice
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− | !Description
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− | |-
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− | |'''Involve Stakeholders'''
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− | |Involve the stakeholders early in the stakeholder requirements development process.
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− | |-
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− | |'''Presence of Rationale'''
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− | |Capture the rationale for each stakeholder requirement.
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− | |-
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− | |'''Analyze Sources before Starting'''
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− | |Complete stakeholder requirements as much as possible before starting the definition of the system requirements.
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− | |-
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− | |'''Modeling Techniques'''
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− | |Use modeling techniques as indicated in sections above.
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− | |-
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− | |'''Requirements Management Tool'''
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− | |Consider using a requirements management tool. This tool should have the capability to trace linkages between the stakeholder requirements and the system requirements and to record the source of each stakeholder requirement.
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− | |}
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− | </center>
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− | ==References==
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| ===Works Cited=== | | ===Works Cited=== |
| + | None. |
| | | |
− | Faisandier, A. 2012. ''Systems Architecture and Design.'' Belberaud, France: Sinergy'Com.
| + | ===Primary References=== |
| + | ANSI/EIA. 1998. ''[[ANSI/EIA 632|Processes for Engineering a System]]''. Philadelphia, PA, USA: American National Standards Institute (ANSI)/Electronic Industries Association (EIA), ANSI/EIA 632-1998. |
| | | |
− | Hauser, J. and D. Clausing. 1988. "The House of Quality." ''Harvard Business Review.'' (May - June 1988).
| + | INCOSE. 2015. '[[INCOSE Systems Engineering Handbook|Systems Engineering Handbook]]: A Guide for System Life Cycle Processes and Activities', version 4.0. Hoboken, NJ, USA: John Wiley and Sons, Inc, ISBN: 978-1-118-99940-0. |
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− | OMG. 2010. ''OMG Systems Modeling Language specification'', version 1.2. Needham, MA: Object Management Group. July 2010.
| + | ISO/IEC/IEEE. 2015. ''[[ISO/IEC/IEEE 15288|Systems and Software Engineering - System Life Cycle Processes]].'' Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), Institute of Electrical and Electronics Engineers. [[ISO/IEC/IEEE 15288]]:2015. |
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− | ISO/IEC/IEEE. 2011. ''Systems and software engineering - Requirements engineering.'' Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission/ Institute of Electrical and Electronics Engineers (IEEE), (IEC), ISO/IEC/IEEE 29148. | + | ISO/IEC/IEEE. 2011. ''[[ISO/IEC/IEEE 29148|Systems and Software Engineering - Requirements Engineering]]''. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission/ Institute of Electrical and Electronics Engineers (IEEE), (IEC), [[ISO/IEC/IEEE 29148]]. |
| | | |
− | ISO/IEC/IEEE. 2015. ''[[ISO/IEC/IEEE 15288|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 15288:2015.
| + | ===Additional References=== |
− | | + | Hitchins, D. 2007. ''Systems Engineering: A 21st Century Systems Methodology.'' Hoboken, NJ, USA: John Wiley & Sons. |
− | ===Primary References=== | |
− | ISO/IEC/IEEE. 2011. ''[[ISO/IEC/IEEE 29148|Systems and software engineering - Requirements engineering]]''. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission/ Institute of Electrical and Electronics Engineers (IEEE), (IEC), ISO/IEC/IEEE 29148.
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− | ISO/IEC/IEEE. 2015. ''[[ISO/IEC/IEEE 15288|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 15288:2015. | + | ''ISO/IEC. 2003. Systems Engineering – A Guide for The Application of ISO/IEC 15288 System Life Cycle Processes''. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), ISO/IEC 19760:2003 (E). http://www.hitchins.net/EmergenceEtc.pdf. |
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− | ISO/IEC/IEEE. 2011. ''[[ISO/IEC/IEEE 42010|Systems and Software Engineering - Architecture Description]]''. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC)/Institute of Electrical and Electronics Engineers (IEEE), [[ISO/IEC/IEEE 42010]]. | + | ISO/IEC. 2007. ''Systems Engineering – Application and Management of The Systems Engineering Process''. Geneva, Switzerland: International Organization for Standards (ISO)/International Electrotechnical Commission (IEC), ISO/IEC 26702:2007. |
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− | ===Additional References===
| + | Jackson, S., D. Hitchins, and H. Eisner. 2010. "What is the Systems Approach?" INCOSE ''Insight.'' (April 2010): 41-43. |
− | Buede, D.M. 2009. ''The engineering design of systems: Models and methods''. 2nd ed. Hoboken, NJ, USA: John Wiley & Sons Inc.
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− | MITRE. 2011. "Requirements Engineering." ''Systems Engineering Guide.'' Accessed 9 March 2012 at http://www.mitre.org/work/systems_engineering/guide/se_lifecycle_building_blocks/requirements_engineering/.
| + | NASA. 2007. ''Systems Engineering Handbook''. Washington, D.C., USA: National Aeronautics and Space Administration (NASA). NASA/SP-2007-6105. |
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− | MITRE. 2011. "Stakeholder Assessment and Management." ''Systems Engineering Guide.'' Accessed 9 March 2012 at http://www.mitre.org/work/systems_engineering/guide/enterprise_engineering/transformation_planning_org_change/stakeholder_assessment_management.html.
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| ---- | | ---- |
− | <center>[[Business or Mission Analysis|< Previous Article]] | [[Concept Definition|Parent Article]] | [[System Definition|Next Article >]]</center> | + | <center>[[Lean Engineering|< Previous Article]] | [[Systems Engineering and Management|Parent Article]] | [[Business or Mission Analysis|Next Article >]]</center> |
| + | |
| + | <center>'''SEBoK v. 2.0, released 1 June 2019'''</center> |
| | | |
− | [[Category:Concept Definition]] | + | [[Category:Part 3]][[Category:Knowledge Area]] |
− | {{DISQUS}}
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ConceptConcept Definition is the set of systems engineering (SE) activities in which the problem space and the needs and requirements of the business or enterprise and stakeholdersstakeholders are closely examined. The activities are grouped and described as generic processes which include Mission Analysis and Stakeholder Needs and Requirements. Concept Definition begins before any formal definition of the system-of-interestsystem-of-interest (SoI) is developed.
Mission AnalysisMission Analysis focuses on the needs and requirements of business or enterprise — that is, on defining the problem or opportunity that exists (in what is often called the problem space or problem situation), as well as understanding the constraints on and boundaries of the selected system when it is fielded (in what is often called the solution space). The Stakeholder Needs and RequirementsStakeholder Needs and Requirements process explores and defines the operational aspects of a potential solution for the stakeholders from their point of view, independent of any specific solution. In these two Concept Definition activities, business or enterprise decision makers and other stakeholders describe what a solution should accomplish and why it is needed. Both why and what need to be answered before consideration is given to how the problem will be addressed (i.e., what type of solution will be implemented) and how the solution will be defined and developed.
If a new or modified system is needed, then System DefinitionSystem Definition activities are performed to assess the system. See Life Cycle Processes and Enterprise Need for further detail on the transformation of needs and requirements from the business or enterprise and stakeholder levels of abstraction addressed in Concept Definition to the system and system element level of abstraction addressed in System Definition.
The specific activities and sequence of Concept Definition activities and their involvement with the life cycle activities of any system, and in particular the close integration with System Definition activities, will be dependent upon the type of life cycle modellife cycle model being utilized. See Applying Life Cycle Processes for further discussion of the concurrent, iterative and recursive nature of these relationships.
Topics
Each part of the SEBoK is divided into knowledge areas (KAs), which are groupings of information with a related theme. The KAs in turn are divided into topics. This KA contains the following topics:
See the article Matrix of Implementation Examples for a mapping of case studies and vignettes included in Part 7 as well as topics covered in Part 3.
Concept Definition Activities
There are two primary activities discussed under concept definition: Mission AnalysisMission Analysis and the definition of Stakeholder Needs and RequirementsStakeholder Needs and Requirements:
- Mission Analysis begins an iteration of the life cycle of a potential SoI that could solve a problem or realize an opportunity for developing a new product, service, or enterprise. These activities assist business or enterprise decision makers to define the problem space, identify the stakeholders, develop preliminary operational concepts, and distinguish environmental conditions and constraints that bound the solution space. In other words, mission analysis takes the enterprise capability gap or opportunity and defines the problem/opportunity in a manner that provides a common understanding encapsulated in what are referred to as “business or mission needs.” Business or mission needs are then used to produce a clear, concise, and verifiable set of business requirements.
- The Stakeholder Needs and Requirements activity works with stakeholders across the life cycle to elicit and capture a set of needs, expectations, goals, or objectives for a desired solution to the problem or opportunity, referred to as "stakeholder needs". The stakeholder needs are used to produce a clear, concise, and verifiable set of stakeholder requirements. Stakeholder needs and requirements identify and define the needs and requirements of the stakeholders in a manner that enables the characterization of the solution alternatives.
Mission Analysis takes the business and stakeholders' needs and requirements and carries the analysis down from problem space to solution space, including concept, mission, and boundary or context so that a solution concept (at the black-box level) can be selected from the alternatives. Figure 1 in the Mission Analysis topic depicts this interaction. The products and artifacts produced during Concept Definition are then used in System DefinitionSystem Definition.
The different aspects of how systems thinkingsystems thinking is applicable to concept definition are discussed in SEBoK Part 2. In particular, the use of a combination of hard systemhard system and soft systemsoft system approaches depending on the type of problem or class of solution is discussed in Identifying and Understanding Problems and Opportunities and the contrast between top-down and bottom-up approaches in Synthesizing Possible Solutions.
Drivers of Solution on Problem Definition: Push Versus Pull
Problem definition and solution design depend on each other. Solutions should be developed to respond appropriately to well-defined problems. Problem definitions should be constrained to what is feasible in the solution space. System AnalysisSystem Analysis activities are used to provide the link between problems and solutions.
There are two paradigms that drive the ways in which concept definition is done: push and pull. The pull paradigm is based on providing a solution to an identified problem or gap, such as a missing mission capability for defense or infrastructure. The push paradigm is based on creating a solution to address a perceived opportunity, such as the emergence of an anticipated product or service that is attractive to some portion of the population (i.e. whether a current market exists or not). This can impact other life cycle processes, such as in verification and validation, or alpha/beta testing as done in some commercial domains.
As systems generally integrate existing and new system elementssystem elements in a mixture of push and pull, it is often best to combine a bottom-up approach with a top-down approach to take into account legacy elements, as well as to identify the services and capabilities that must be provided in order to define applicable interface requirements and constraints. This is discussed in Applying Life Cycle Processes.
References
Works Cited
None.
Primary References
ANSI/EIA. 1998. Processes for Engineering a System. Philadelphia, PA, USA: American National Standards Institute (ANSI)/Electronic Industries Association (EIA), ANSI/EIA 632-1998.
INCOSE. 2015. 'Systems Engineering Handbook: A Guide for System Life Cycle Processes and Activities', version 4.0. Hoboken, NJ, USA: John Wiley and Sons, Inc, ISBN: 978-1-118-99940-0.
ISO/IEC/IEEE. 2015. Systems and Software Engineering - System Life Cycle Processes. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), Institute of Electrical and Electronics Engineers. ISO/IEC/IEEE 15288:2015.
ISO/IEC/IEEE. 2011. Systems and Software Engineering - Requirements Engineering. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission/ Institute of Electrical and Electronics Engineers (IEEE), (IEC), ISO/IEC/IEEE 29148.
Additional References
Hitchins, D. 2007. Systems Engineering: A 21st Century Systems Methodology. Hoboken, NJ, USA: John Wiley & Sons.
ISO/IEC. 2003. Systems Engineering – A Guide for The Application of ISO/IEC 15288 System Life Cycle Processes. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), ISO/IEC 19760:2003 (E). http://www.hitchins.net/EmergenceEtc.pdf.
ISO/IEC. 2007. Systems Engineering – Application and Management of The Systems Engineering Process. Geneva, Switzerland: International Organization for Standards (ISO)/International Electrotechnical Commission (IEC), ISO/IEC 26702:2007.
Jackson, S., D. Hitchins, and H. Eisner. 2010. "What is the Systems Approach?" INCOSE Insight. (April 2010): 41-43.
NASA. 2007. Systems Engineering Handbook. Washington, D.C., USA: National Aeronautics and Space Administration (NASA). NASA/SP-2007-6105.
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SEBoK v. 2.0, released 1 June 2019