Business and Mission Analysis
Concept definition is the set of systems engineering (SE) activities in which the problem space and the needs of the stakeholders are closely examined. This occurs before any formal definition of the system-of-interest (SoI) is developed.
Mission Analysis focuses on defining the problem or opportunity that exists (often called the problem space), as well as understanding the constraints on and boundaries of the solution space. It examines why a solution is desired and what problem or opportunity it will address.
Stakeholder Needs and Requirements explores and defines the operational aspects of a potential solution for the stakeholders from their point of view, independent of any specific solution. It describes what a solution should accomplish. 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) and how the solution will be defined and developed. If the chosen solution is a new or modified system, then system definition activities are performed to define the system.
Various authors use different terms to describe these phases. For example, Kossiakoff and Sweet (2005) call them needs analysis and concept exploration.
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 to topics covered in Part 3.
Concept Definition Activities
There are two primary activities discussed under concept definition: mission analysis and the definition of stakeholder needs and requirements:
- Mission Analysis initiates 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 define the problem space, identify the stakeholders, develop preliminary operational concepts, and identify 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.
- Stakeholder Needs and Requirements 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, called "stakeholder needs". The stakeholder needs are used to produce a clear, concise, and verifiable set of stakeholder requirements. Stakeholder needs and requirements identifies and defines the needs and requirements of the stakeholders in a manner that enables characterizing the solution alternatives.
Mission analysis then takes the stakeholder's needs and requirements and carries the analysis down from problem space to solution space, including concept, requirement (stakeholder/mission) and boundary or context so that a solution concept (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 definition.
Top-Down Approach: from Problem to Solution
In a top-down approach, concept definition activities are focused primarily on understanding the problem, the operational needs/requirements within the problem space, and the conditions that constrain the solution and bound the solution space. The concept definition activities determine whether a new or modified system (i.e., the SoI) is needed to fulfill the need. The system definition activities use the outcomes of concept definition and are focused on defining the system through a set of system requirements, logical and physical architectures, and the design of solutions.
Outcomes of system definition are used for system realization, system deployment and use, and product and service life management. In this approach, system definition includes activities that are completed primarily in the front-end portion of system development and the design itself. Top-down activities can be sequential, iterative, recursive or evolutionary. These activities are based on the results of mission analysis and the definition of stakeholder needs and requirements and generally consist of the development of system requirements.
These system requirements are then used as inputs for the logical architecture design, which includes functional, behavioral, temporal, and physical architectural aspects. System analysis studies are performed to evaluate and select the most suitable potential system elements. System analysis is intended to provide a best-value, balanced solution involving all relevant engineering elements (stakeholder requirements, system requirements, and design properties).
For the concept definition, an appropriate architecture framework representation can be useful in the visualization and analysis of the mission and solution requirements. These include the U.S. Department of Defense Architecture Framework (DoDAF) operations view (DoD 2010), the Zachman Framework (Rows1 and 2) (Zachman 2008), and The Open Group Architecture Framework(TOGAF) Architecture Development Method (ADM) (The Open Group 2010) Phases A and B within the concept definition when performing mission analysis and evaluating stakeholder needs and requirements.
Bottom-Up Approach: Evolution of the Solution
In some situations, the concept definition activities determine the need to evolve existing capabilities or add new capabilities to an existing system. During the concept definition, the alternatives to address the need are evaluated. Engineers are then led to reconsider the system definition in order to modify or adapt some structural, functional, behavioral, or temporal properties during the product or service life cycle for a changing context of use or for the purpose of improving existing solutions.
reverse engineering is often necessary to enable system engineers to (re)characterize the properties of the system of interest (SoI) or its elements. This is an important step to ensure that system engineers understand the SoI before beginning modification. (For more information on system definition, see the System Definition article.)
A bottom-up approach is necessary for analysis purposes, or for (re)using existing elements in the design architecture . Changes in the context of use or a need for improvement can prompt this. In contrast, a top-down approach is generally used to define an initial design solution corresponding to a problem or a set of needs.
Bottom-up and top-down approaches can be, and often are, mixed.
Drivers of Solutions: Push versus Pull
There are two paradigms that drive the concept definition - '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 a product or service anticipated to be wanted by or attractive to some portion of the population (i.e. whether a current market exists or not). This can have an effect on other lifecycle processes, as in verification and validation as it is performed in defense industries versus alpha/beta testing done in some commercial domains.
Separation and Iteration between Problem and Solution
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 analysis activities are used to perform the link between problems and solutions.
As systems generally integrate existing and new system elements , a bottom-up approach can be combined with a top-down approach to take into account legacy elements, as well as to identify the services and capabilities they provide in order to define applicable interface requirements and constraints. As discussed in System Life Cycle Process Models: Iterative, this is iterative for these evolutionary systems.
References
Works Cited
DoD. 2010. DoD Architecture Framework, version 2.02. Arlington, VA: U.S. Department of Defense. Accessed August 29, 2012. Available at: http://dodcio.defense.gov/Portals/0/Documents/DODAF/DoDAF_v2-02_web.pdf.
Hitchins, D. 2007. Systems Engineering: A 21st Century Systems Methodology. Hoboken, NJ, USA: John Wiley & Sons.
Jackson, S., D. Hitchins, and H. Eisner. 2010. "What is the Systems Approach?" INCOSE Insight (April 2010): 41-43.
Kossiakoff, A, and W. Sweet. 2009. Systems Engineering: Principles and Practice. Hoboken, NJ, USA: John Wiley and Sons.
The Open Group. 2011. TOGAF, version 9.1. Hogeweg, The Netherlands: Van Haren Publishing. Accessed August 29, 2012. Available at: https://www2.opengroup.org/ogsys/jsp/publications/PublicationDetails.jsp?catalogno=g116.
Zachman, J. 2008. "John Zachman's Concise Definition of The Zachman Framework™ (online)". Zachman International Enterprise Architecture. Accessed August 29, 2012. Available at: http://www.zachman.com/about-the-zachman-framework.
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. 2011. INCOSE Systems Engineering Handbook: A Guide for System Life Cycle Processes and Activities. Version 3.2.1. San Diego, CA, USA: International Council on Systems Engineering (INCOSE), INCOSE-TP-2003-002-03.2.1.
ISO/IEC/IEEE. 2008. Systems and Software Engineering - System Life Cycle Processes. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electronical Commission (IEC), Institute of Electrical and Electronics Engineers. ISO/IEC/IEEE 15288:2008 (E).
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
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 Electronical Commission (IEC), ISO/IEC 19760:2003 (E).
ISO/IEC. 2007. Systems Engineering – Application and Management of The Systems Engineering Process. Geneva, Switzerland: International Organization for Standards (ISO)/International Electronical 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. Hitchins, D. 2007. Systems Engineering: A 21st Century Systems Methodology. Hoboken, NJ, USA: John Wiley & Sons.
SEBoK Discussion
Please provide your comments and feedback on the SEBoK below. You will need to log in to DISQUS using an existing account (e.g. Yahoo, Google, Facebook, Twitter, etc.) or create a DISQUS account. Simply type your comment in the text field below and DISQUS will guide you through the login or registration steps. Feedback will be archived and used for future updates to the SEBoK. If you provided a comment that is no longer listed, that comment has been adjudicated. You can view adjudication for comments submitted prior to SEBoK v. 1.0 at SEBoK Review and Adjudication. Later comments are addressed and changes are summarized in the Letter from the Editor and Acknowledgements and Release History.
If you would like to provide edits on this article, recommend new content, or make comments on the SEBoK as a whole, please see the SEBoK Sandbox.
blog comments powered by Disqus