Difference between revisions of "Generic Life Cycle Model"

Latest revision as of 21:48, 2 May 2024

Lead Authors: Kevin Forsberg, Richard Turner, Contributing Author: Rick Adcock

As discussed in the generic life cycle paradigm in System Life Cycle Approaches, each system-of-interestsystem-of-interest (SoI) has an associated life cycle modellife cycle model. The generic life cycle model below applies to a single SoI. SE must generally be synchronized across a number of tailored instances of such life cycle models to fully satisfy stakeholder needs. More complex life cycle models which address this are described in Life Cycle Models.

A Generic System Life Cycle Model

There is no single “one-size-fits-all” system life cycle model that can provide specific guidance for all project situations. Figure 1, adapted from (Lawson 2010, ISO 2015, and ISO 2010), provides a generic life cycle model that forms a starting point for the most common versions of pre-specified, evolutionary, sequential, opportunistic, and concurrent life cycle processes. The model is defined as a set of stages, within which technical and management activities are performed. The stages are terminated by decision gatesdecision gates, where the key stakeholders decide whether to proceed into the next stage, to remain in the current stage, or to terminate or re-scope related projects.

Figure 1. A Generic Life Cycle Model. (SEBoK Original)

Elaborated definitions of these stages are provided in the glossary below and in various other ways in subsequent articles.

The Concept Definition stage begins with a decision by a protagonist (individual or organization) to invest resources in a new or improved engineered systemengineered system. Inception begins with a set of stakeholdersstakeholders agreeing to the need for change to an engineered system context and exploring whether new or modified SoI can be developed, in which the life cyclelife cycle benefits are worth the investments in the life cycle costslife cycle costs. Activities include: developing the concept of operations and business case; determining the key stakeholders and their desired capabilities; negotiating the stakeholder requirements among the key stakeholders and selecting the system’s non-developmental items (NDIs).

The System Definition stage begins when the key stakeholders decide that the business needs and stakeholder requirements are sufficiently well defined to justify committing the resources necessary to define a solution options in sufficient detail to answer the life cycle cost question identified in concept definition and provide a basis of system realization if appropriate. Activities include developing system architectures; defining and agreeing upon levels of system requirements; developing systems-level life cycle plans and performing system analysis in order to illustrate the compatibility and feasibility of the resulting system definition. The transition into the system realization stage can lead to either single-pass or multiple-pass development.

It should be noted that the concept and system definition activities above describe activities performed by systems engineers when performing systems engineering. There is a very strong concurrency between proposing a problem situation or opportunity and describing one or more possible system solutions, as discussed in Systems Approach Applied to Engineered Systems. Other related definition activities include: prototyping or actual development of high-risk items to show evidence of system feasibility; collaboration with business analysts or performing mission effectiveness analyses to provide a viable business case for proceeding into realization; and modifications to realized systems to improve their production, support or utilization. These activities will generally happen through the system life cycle to handle system evolution, especially under multiple-pass development. This is discussed in more detail in the Life Cycle Models knowledge area.

The System Realization stage begins when the key stakeholders decide that the SoI architecture and feasibility evidence are sufficiently low-risk to justify committing the resources necessary to develop and sustain the initial operational capability (IOC) or the single-pass development of the full operational capability (FOC). Activities include: construction of the developmental elements; integration of these elements with each other and with the non-developmental item (NDI) elements; verification and validation of the elements and their integration as it proceeds; and preparing for the concurrent production, support, and utilization activities.

The System Production, Support, and Utilization (PSU) stages begin when the key stakeholders decide that the SoI life-cycle feasibility and safety are at a sufficiently low-risk level that justifies committing the resources necessary to produce, field, support, and utilize the system over its expected lifetime. The lifetimes of production, support, and utilization are likely to be different. After market support will generally continue after production is complete and users will often continue to use unsupported systems.

System Production involves the fabrication of instances or versions of an SoI and of associated after-market spare parts. It also includes production quality monitoring and improvement; product or service acceptance activities; and continuous production process improvement. It may include low-rate initial production (LRIP) to mature the production process or to promote the continued preservation of the production capability for future spikes in demand.

Systems Support includes various classes of maintenance: corrective (for defects), adaptive (for interoperability with independently evolving co-dependent systems), and perfective (for enhancement of performance, usability, or other key performance parameters). It also includes hot lines and responders for user or emergency support and the provisioning of needed consumables (gas, water, power, etc.). Its boundaries include some gray areas, such as the boundary between small system enhancements and the development of larger complementary new additions, and the boundary between rework/maintenance of earlier fielded increments in incremental or evolutionary development. Systems Support usually continues after System Production is terminated.

System Utilization includes the use of the SoI in its context by operators, administrators, the general public, or systems above it in the system-of-interest hierarchy. It usually continues after Systems Support is terminated.

The System Retirement stage is often executed incrementally as system versions or elements become obsolete or are no longer economical to support and therefore undergo disposal or recycling of their content. Increasingly affordable considerations make system re-purposing an attractive alternative.

Applying the Life Cycle Model

Figure 1 shows just the single-step approach for proceeding through the stages of a SoI life cycle. In the Life Cycle Models knowledge area, we discuss examples of real-world enterprises and their drivers, both technical and organizational. These have led to a number of documented approaches for sequencing the life cycle stages to deal with some of the issues raised. The Life Cycle Models KA summarizes a number of incrementalincremental and evolutionaryevolutionary life cycle models, including their main strengths and weaknesses, and also discusses criteria for choosing the best-fit approach.

In Figure 1, we have listed key technical and management activities critical to successful completion of each stage. This is a useful way to illustrate the goals of each stage and gives an indication of how processes align with these stages. This can be important when considering how to plan for resources, milestones, etc. However, it is important to observe that the execution of process activities is not compartmentalized to particular life cycle stages (Lawson 2010). In Applying Life Cycle Processes, we discuss a number of views on the nature of the inter-relationships between process activities within a life cycle model. In general, the technical and management activities are applied in accordance with the principles of concurrencyconcurrency, iterationiteration and recursionrecursion described in the generic life cycle paradigm.

References

Works Cited

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 15288:2015.

ISO/IEC. 2010. Systems and Software Engineering, Part 1: Guide for Life Cycle Management. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), ISO/IEC 24748-1:2010.

Lawson, H. 2010. A Journey Through the Systems Landscape. London, UK: College Publications.

Primary References

Forsberg, K., H. Mooz, H. Cotterman. 2005. Visualizing Project Management, 3rd Ed. Hoboken, NJ: J. Wiley & Sons.

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.

Lawson, H. 2010. A Journey Through the Systems Landscape. London, UK: College Publications.

Additional References

None.

< Previous Article | Parent Article | Next Article > SEBoK v. 2.10, released 06 May 2024

@@ Line 1: / Line 1: @@
-As discussed in the generic life cycle paradigm in [[Introduction to Life Cycle Processes]] each [[System-of-Interest (glossary)]] has an associated [[Life Cycle Model (glossary)]]. The generic life cycle model below applies to a single SoI.  SE must generally be synchronised across a number of such life cycle models to fully satisfy stakeholder needs.  More complex life cycle models which address this are described in [[Life Cycle Models]].
+----
+'''''Lead Authors:''''' ''Kevin Forsberg, Richard Turner'', '''''Contributing Author:''''' ''Rick Adcock''
+----
+As discussed in the generic life cycle paradigm in [[System Life Cycle Approaches]], each {{Term|System-of-Interest (glossary)}} (SoI) has an associated {{Term|Life Cycle Model (glossary)}}. The generic life cycle model below applies to a single SoI.  SE must generally be synchronized across a number of tailored instances of such life cycle models to fully satisfy stakeholder needs.  More complex life cycle models which address this are described in [[Life Cycle Models]].
 ==A Generic System Life Cycle Model==
-There is no single “one-size-fits-all” system life cycle model that can provide specific guidance for all project situations.  Figure 1, adapted from (Lawson 2010, ISO/IEC 2008, and ISO/IEC 2010), provides a generic life cycle model that forms a starting point for the most common versions of pre-specified, evolutionary, sequential, opportunistic, and concurrent life cycle processes.  The model is defined as a set of stages, within which technical and management activities are performed.  The stages are terminated by [[Decision Gate (glossary)|decision gates]] where the key stakeholders decide whether to proceed into the next stage, to remain in the current stage, or to terminate or re-scope related projects.
+There is no single “one-size-fits-all” system life cycle model that can provide specific guidance for all project situations.  Figure 1, adapted from (Lawson 2010, ISO 2015, and ISO 2010), provides a generic life cycle model that forms a starting point for the most common versions of pre-specified, evolutionary, sequential, opportunistic, and concurrent life cycle processes.  The model is defined as a set of stages, within which technical and management activities are performed.  The stages are terminated by {{Term|Decision Gate (glossary)|decision gates}}, where the key stakeholders decide whether to proceed into the next stage, to remain in the current stage, or to terminate or re-scope related projects.
 [[File:Fig_1_A_generic_life_cycle_KF.png|thumb|600px|center|'''Figure 1.  A Generic Life Cycle Model.''' (SEBoK Original)]]
-Elaborated definitions of these stages are provided below, in the glossary, and in various other ways in subsequent articles.
+Elaborated definitions of these stages are provided in the glossary below and in various other ways in subsequent articles.
-The '''Concept Definition''' stage begins with a decision by a protagonist (individual or organization) to invest resources in a new or improved system. Inception begins with a set of [[Stakeholder (glossary)|stakeholders]] agreeing to the need for a system and exploring whether a new or modified system can be developed, in which the [[Life Cycle (glossary)|life cycle]] benefits are worth the investments in the [[Life Cycle Cost (LCC) (glossary)|life cycle costs]].  Activities include: developing the concept of operations and business case; determining the key stakeholders and their desired capabilities; negotiating the stakeholder requirements among the key stakeholders and selecting the system’s non-developmental items (NDIs).
+The '''Concept Definition''' stage begins with a decision by a protagonist (individual or organization) to invest resources in a new or improved {{Term|Engineered System (glossary)|engineered system}}. Inception begins with a set of {{Term|Stakeholder (glossary)|stakeholders}} agreeing to the need for change to an [[Engineered System Context|engineered system context]] and exploring whether new or modified SoI can be developed, in which the {{Term|Life Cycle (glossary)|life cycle}} benefits are worth the investments in the {{Term|Life Cycle Cost (LCC) (glossary)|life cycle costs}}. Activities include: developing the concept of operations and business case; determining the key stakeholders and their desired capabilities; negotiating the stakeholder requirements among the key stakeholders and selecting the system’s non-developmental items (NDIs).
-The '''System Definition''' stage begins when the key stakeholders decide that the business needs and stakeholder requirements are sufficiently well defined to justify committing the resources necessary to define a whole system solution in sufficient detail to answer the life cycle cost questions identified in concept definition and provide a basis of system realization if appropriate.  Activities include developing the system’s architecture; defining and agreeing levels of system requirements; developing systems-level life cycle plans and performing system analysis in order to illustrate the compatibility and feasibility of the resulting system definition. The transition into the system realization stage can lead to either single-pass or multiple-pass development.
+The '''System Definition''' stage begins when the key stakeholders decide that the business needs and stakeholder requirements are sufficiently well defined to justify committing the resources necessary to define a solution options in sufficient detail to answer the life cycle cost question identified in concept definition and provide a basis of system realization if appropriate.  Activities include developing system architectures; defining and agreeing upon levels of system requirements; developing systems-level life cycle plans and performing system analysis in order to illustrate the compatibility and feasibility of the resulting system definition. The transition into the system realization stage can lead to either single-pass or multiple-pass development.
 It should be noted that the concept and system definition activities above describe activities performed by ''systems engineers'' when performing ''systems engineering''.  There is a very strong concurrency between proposing a problem situation or opportunity and describing one or more possible system solutions, as discussed in [[Systems Approach Applied to Engineered Systems]].  Other related definition activities include: prototyping or actual development of high-risk items to show evidence of system feasibility; collaboration with business analysts or performing mission effectiveness analyses to provide a viable business case for proceeding into realization; and modifications to realized systems to improve their production, support or utilization.  These activities will generally happen through the system life cycle to handle system evolution, especially under multiple-pass development.  This is discussed in more detail in the [[Life Cycle Models]] knowledge area.
-The '''System Realization''' stage begins when the key stakeholders decide that the system elements and feasibility evidence are sufficiently low-risk to justify committing the resources necessary to develop and sustain the initial operational capability (IOC) or the single-pass development of the full operational capability (FOC).  Activities include: construction of the developmental elements; integration of these with each other and with the non-developmental item (NDI) elements; verification and validation (V&V) of the elements and their integration as it proceeds; and preparing for the concurrent production, support, and utilization activities.
+The '''System Realization''' stage begins when the key stakeholders decide that the SoI architecture and feasibility evidence are sufficiently low-risk to justify committing the resources necessary to develop and sustain the initial operational capability (IOC) or the single-pass development of the full operational capability (FOC).  Activities include: construction of the developmental elements; integration of these elements with each other and with the non-developmental item (NDI) elements; verification and validation of the elements and their integration as it proceeds; and preparing for the concurrent production, support, and utilization activities.
-The '''System Production, Support, and Utilization (PSU)''' stages begins when the key stakeholders decide that the system life-cycle feasibility and safety illustrate a sufficiently low-risk level that justifies committing the resources necessary to produce, field, support, and utilize the system over its expected lifetime.  The lifetimes of production, support, and utilization are likely to be different.  Aftermarket support will generally continue after production is complete and users will often continue to use unsupported systems.
+The '''System Production, Support, and Utilization (PSU)''' stages begin when the key stakeholders decide that the SoI life-cycle feasibility and safety are at a sufficiently low-risk level that justifies committing the resources necessary to produce, field, support, and utilize the system over its expected lifetime.  The lifetimes of production, support, and utilization are likely to be different. After market support will generally continue after production is complete and users will often continue to use unsupported systems.
-'''System Production''' involves the fabrication of system copies or versions and of associated aftermarket spare parts.  It also includes production quality monitoring and improvement; product or service acceptance activities; and continuous production process improvement. It may include low-rate initial production (LRIP) to mature the production process or to promote the continued preservation of the production capability for future spikes in demand.
+'''System Production''' involves the fabrication of instances or versions of an SoI and of associated after-market spare parts.  It also includes production quality monitoring and improvement; product or service acceptance activities; and continuous production process improvement. It may include low-rate initial production (LRIP) to mature the production process or to promote the continued preservation of the production capability for future spikes in demand.
 '''Systems Support''' includes various classes of maintenance: corrective (for defects), adaptive (for interoperability with independently evolving co-dependent systems), and perfective (for enhancement of performance, usability, or other key performance parameters).  It also includes hot lines and responders for user or emergency support and the provisioning of needed consumables (gas, water, power, etc.).  Its boundaries include some gray areas, such as the boundary between small system enhancements and the development of larger complementary new additions, and the boundary between rework/maintenance of earlier fielded increments in incremental or evolutionary development. ''Systems Support'' usually continues after ''System Production'' is terminated.
-'''System Utilization''' includes the use of the system by operators, administrators, the general public, or systems above it in the system-of-interest hierarchy.  It usually continues after ''Systems Support'' is terminated.
+'''System Utilization''' includes the use of the SoI in its context by operators, administrators, the general public, or systems above it in the system-of-interest hierarchy.  It usually continues after ''Systems Support'' is terminated.
 The '''System Retirement''' stage is often executed incrementally as system versions or elements become obsolete or are no longer economical to support and therefore undergo disposal or recycling of their content.  Increasingly affordable considerations make system re-purposing an attractive alternative.
-==Life Cycle Process Terminology==
+==Applying the Life Cycle Model==
-===Requirement===
-A [[Requirement (glossary)|requirement]] is something that is needed or wanted, but may not be compulsory in all circumstances. Requirements may refer to product or process characteristics or constraints.  Different understandings of requirements are dependent on process state, level of abstraction, and type (e.g. functional, performance, constraint).  An individual requirement may also have multiple interpretations over time.
-Requirements exist at multiple levels of enterprise or system with multiple levels af bstraction.  This ranges from the highest level of the enterprise capability or customer need to the lowest level of the system design .Thus, requirements need to be defined at the appropriate level of detail for the level of the entity to which it applies. See the article [[Transforming Enterprise Need to Requirements]] for further detail on the transformation of needs and requirements from the enterprise to the lowest system element across concept definition and system definition.
-===Architecture===
-An [[Architecture (glossary)|architecture]] refers to the organizational structure of a system, whereby the system can be defined in different contexts.  Architecting is the art or practice of designing the structures. See the article [[Iterative and Recursive System Definition]] for further discussion on the use of levels of Logical and Physical architecture to define related system and system elements; and support the requirements activities.
-Architectures can apply for a system, product, enterprise, or service.  For example, Part 3 mostly considers product-related architectures that systems engineers create, but enterprise architecture describes the structure of an organization.  [[Enabling Systems Engineering|Part 5: Enabling Systems Engineering]] interprets enterprise architecture in a much broader manner than an IT system used across an organization, which is a specific instance of architecture.
-Frameworks are closely related to architectures, as they are ways of representing architectures.  The terms Architecture Framework and Architectural Framework both refer to the same.  Examples include:  DoDAF, MoDAF, NAF for representing systems in defense applications, the TOGAF open group Architecture Framework, and the Federal Enterprise Architecture Framework (FEAF) for information technology acquisition, use and disposal.  See the glossary of terms [[Architecture Framework (glossary)|Architecture Framework]] for definition and other examples.
-===Other Processes===
-A number of other life cycle processes are mentioned above, including [[System Analysis (glossary)]], [[Integration (glossary)]], [[Verification (glossary)]], [[Validation (glossary)]], deployment, operation, [[Maintenance (glossary)]] and [[Disposal (glossary)]] are discussed in detail in the [[System Realization]] and [[System Deployment and Use]] knowledge areas.
-==Life Cycle Process Sequence==
-In the above description we have listed key activities critical to successful completion of each stage. This is a useful way to illustrate the goals of each stage and gives an indication of how processes align with these stages.  This can be important when considering how to plan for resources, milestones, etc.  However, it is important to observe that the execution of process activities are not compartmentalized to particular life cycle stages (Lawson 2010).
-Figure 2 show a simple illustration of the through life nature of technical an management processes.  This figure builds directly on the "hump diagram" principles described in [[Systems Approach Applied to Engineered Systems]].
-insert figure here
-The lines on this diagram represent the amount of activity for each process over the generic life cycle. The peaks (or humps) of activity represent the periods when a process activity becomes the main focus of a stage.  The activity before and after these peaks may represent through life issues raised by a process focus, e.g. how will likely maintenance constraints be represented in the system requirements, these considerations help maintain a more holistic perspective in each stage.  Or they can represent forward planning to ensure the resources needed to complete future activities have been included in estimates and plans, e.g. are all resources need for verification in place or available. Ensuring this hump diagram principle is implemented in a way which is achievable, affordable and appropriate to the situation is a critical driver for all life cycle models.
-==Type of Value Added Products/Services==
-Figure 1 shows just the single-step approach for proceeding through the stages of a system’s life cycle.  Adding value (as a product, a service, or both), is a shared purpose among all enterprises, whether public or private, for profit or non-profit. Value is produced by providing and integrating the elements of a system into a product or service according to the system description and transitioning it into productive use. These value considerations will lead to various forms of the generic life cycle management approach in Figure 1. Some examples are as follows (Lawson 2010):
-* A manufacturing enterprise produces nuts, bolts, and lock washer products and then sells their products as value added elements to be used by other enterprises; in turn, these enterprises integrate these products into their more encompassing value added system, such as an aircraft or an automobile. Their requirements will generally be pre-specified by the customer or by industry standards.
-* A wholesaling or retailing enterprise offers products to their customers. Its customers (individuals or enterprises) acquire the products and use them as elements in their systems.  The enterprise support system will likely evolve opportunistically, as new infrastructure capabilities or demand patterns emerge.
-* A commercial service enterprise such as a bank sells a variety of ''products'' as services to their customers; for example, this includes current accounts, savings accounts, loans, and investment management. These services add value and are incorporated into customer systems of individuals or enterprises. The service enterprise’s support system will also likely evolve opportunistically, as new infrastructure capabilities or demand patterns emerge.
-* A governmental service enterprise provides citizens with services that vary widely, but may include services such as health care, highways and roads, pensions, law enforcement, or defense. Where appropriate, these services become infrastructure elements utilized in larger encompassing systems of interest to individuals and/or enterprises.  Major initiatives, such as a next-generation air traffic control system or a metropolitan-area crisis management system (hurricane, typhoon, earthquake, tsunami, flood, fire), will be sufficiently complex enough to follow an evolutionary development and fielding approach. At the element level, there will likely be pre-specified single-pass life cycles.
-* For aircraft and automotive systems, there would likely be a pre-specified multiple-pass life cycle to capitalize on early capabilities in the first pass, but architected to add further value-adding capabilities in later passes.
-* A diversified software development enterprise provides software products that meet stakeholder requirements (needs), thus providing services to product users.  It will need to be developed to have capabilities that can be tailored to be utilized in different customers’ life-cycle approaches and also with product-line capabilities that can be quickly and easily applied to similar customer system developments. Its business model may also include providing the customer with system life-cycle support and evolution capabilities.
-Within these examples, there are systems that remain stable over reasonably long periods of time and those that change rapidly. The diversity represented by these examples and their processes illustrate why there is no one-size-fits-all process that can be used to define a specific systems life cycle. Management and leadership approaches must consider the type of systems involved, their longevity, and the need for rapid adaptation to unforeseen changes, whether in competition, technology, leadership, or mission priorities. In turn, the management and leadership approaches impact the type and number of life cycle models that are deployed as well as the processes that will be used within any particular life cycle.
+Figure 1 shows just the single-step approach for proceeding through the stages of a SoI life cycle. In the [[Life Cycle Models]] knowledge area, we discuss examples of real-world enterprises and their drivers, both technical and organizational.  These have led to a number of documented approaches for sequencing the life cycle stages to deal with some of the issues raised.  The Life Cycle Models KA summarizes a number of {{Term|Incremental (glossary)|incremental}} and {{Term|Evolutionary (glossary)|evolutionary}} life cycle models, including their main strengths and weaknesses, and also discusses criteria for choosing the best-fit approach.
-There are several incremental and evolutionary approaches for sequencing the life cycle stages to deal with some of the issues raised above.  The [[Life Cycle Models]] knowledge area summarizes a number of [[Incremental (glossary)|incremental]] and [[Evolutionary (glossary)|evolutionary]] life cycle models, including their main strengths and weaknesses and also discusses criteria for choosing the best-fit approach.
+In Figure 1, we have listed key technical and management activities critical to successful completion of each stage. This is a useful way to illustrate the goals of each stage and gives an indication of how processes align with these stages.  This can be important when considering how to plan for resources, milestones, etc.  However, it is important to observe that the execution of process activities is not compartmentalized to particular life cycle stages (Lawson 2010).  In [[Applying Life Cycle Processes]], we discuss a number of views on the nature of the inter-relationships between process activities within a life cycle model. In general, the technical and management activities are applied in accordance with the principles of {{Term|Concurrent (glossary)|concurrency}}, {{Term|Iteration (glossary)}} and {{Term|Recursion (glossary)}} described in the [[System Life Cycle Approaches|generic life cycle paradigm]].
 ==References==
 ===Works Cited===
-Anderson, D. 2010. ''Kanban.'' Sequim, WA: Blue Hole Press.
+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|ISO/IEC 15288]]:2015.
-Beck, K. 1999. ''Extreme Programming Explained.'' Boston, MA: Addison Wesley.
+ISO/IEC. 2010. Systems and Software Engineering, Part 1: Guide for Life Cycle Management.  Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC), ISO/IEC 24748-1:2010.
-Boehm, B. and J. Lane. 2007. “Using the Incremental Commitment Model to Integrate System Acquisition, Systems Engineering, and Software Engineering.” ''CrossTalk''. October 2007: 4-9.
-Booher, H. (ed.) 2003. ''Handbook of Human Systems Integration''. Hoboken, NJ, USA: Wiley.
-Checkland, P. 1999. ''Systems Thinking, Systems Practice,'' 2nd ed. Hoboken, NJ, USA: Wiley.
-Cusumano, M., and D. Yoffie 1998. ''Competing on Internet Time'', New York, NY, USA: The Free Press.
-Forsberg, K. and H. Mooz. 1991. "The Relationship of System Engineering to the Project Cycle," ''Proceedings of NCOSE'', October 1991.
-Forsberg, K., H. Mooz, and H. Cotterman. 2005. ''Visualizing Project Management'', 3rd ed. Hoboken, NJ: J. Wiley & Sons.
-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|ISO/IEC 15288]]:2015.
 Lawson, H. 2010. ''A Journey Through the Systems Landscape.'' London, UK: College Publications.
-Ohno, T. 1988. ''Toyota Production System''. New York, NY: Productivity Press.
-Oppenheim, B. 2011.  ''Lean for Systems Engineering.'' Hoboken, NJ: Wiley.
-Pew, R. and A. Mavor (eds.). 2007. ''Human-System Integration in The System Development Process: A New Look.'' Washington, DC, USA: The National Academies Press.
-Warfield, J. 1976. ''Systems Engineering''. Washington, DC, USA: US Department of Commerce (DoC).
-Whadcock, I. 2012. “A third industrial revolution.” ''The Economist.'' April 21, 2012.
-Womack, J.P., D.T. Jones, and D. Roos 1990. ''The Machine That Changed the World: The Story of Lean Production.'' New York, NY, USA: Rawson Associates.
 ===Primary References===
-Blanchard, B.S., and W.J. Fabrycky. 2011. ''[[Systems Engineering and Analysis]]'', 5th ed. Prentice-Hall International series in Industrial and Systems Engineering. Englewood Cliffs, NJ, USA: Prentice-Hall.
 Forsberg, K., H. Mooz, H. Cotterman. 2005. ''[[Visualizing Project Management]]'', 3rd Ed. Hoboken, NJ: J. Wiley & Sons.
-INCOSE. 2012. ''[[INCOSE Systems Engineering Handbook | Systems Engineering Handbook]]'', version 3.2.2. San Diego, CA, USA: International Council on Systems Engineering (INCOSE). INCOSE-TP-2003-002-03.2.2.
+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.
 Lawson, H. 2010. ''[[A Journey Through the Systems Landscape]].''  London, UK:  College Publications.
-Pew, R. and A. Mavor (eds.). 2007. ''[[Human-System Integration in the System Development Process|Human-System Integration in The System Development Process: A New Look]].'' Washington, DC, USA: The National Academies Press.
 ===Additional References===
-Chrissis, M., M. Konrad, and S. Shrum. 2003. ''CMMI: Guidelines for Process Integration and Product Improvement.'' New York, NY, USA: Addison Wesley.
+None.
-Larman , C. and B. Vodde. 2009. ''Scaling Lean and Agile Development.'' New York, NY, USA: Addison Wesley.
 ----
-<center>[[Introduction to Life Cycle Processes|< Previous Article]] | [[Introduction to Life Cycle Processes|Parent Article]] | [[Applying SE across the Enterprise|Next Article >]]</center>
+<center>[[System Life Cycle Approaches|< Previous Article]] | [[System Life Cycle Approaches|Parent Article]] | [[Applying Life Cycle Processes|Next Article >]]</center>
-{{DISQUS}}
+<center>'''SEBoK v. 2.10, released 06 May 2024'''</center>
 [[Category: Part 3]][[Category:Topic]]
-[[Category:Life Cycle Processes]]
+[[Category:System Life Cycle Approaches]]