Configuration Items vary widely in complexity, size and type, from an aircraft, ship, tank, or electronic system to a test meter or a round of ammunition. Regardless of form, size or complexity, the configuration of an item is documented and controlled. Configuration Item selection separates system components into identifiable subsets for the purpose of further development.
For each item, associated configuration documentation ranges from a performance specification to a detailed drawing to a commercial item description. Configuration status update changes will be controlled, accounted, maintained and performance verified.
To define and control the performance of a system or Configuration Item does not mean all components must be designated as Configuration Items, nor does it mean that the performance requirements for the non-Configuration Item components must be under DoD control.
The requirements to be met by a lower-level component not designated as a Configuration Item are established and controlled via the Contractors design and engineering release process. DoD control occurs only when changes to the lower level components impact the baselined performance specification for the Configuration Item
Initial Configuration Item selection should reflect an optimum administrative level during early acquisition. Initially, for Engineering and Manufacturing Development, Configuration Items usually are the deliverable, and separately installable units of the system and other items requiring significant attention at Buyer/Seller interfaces.
During Production, Fielding/Deployment and Operational Support, individual items required for logistics support and designated for separate procurement are also Configuration Items The view of what is designated a Configuration Item may depend on where in the contracting network the view originates. When DoD acquires a system using detail, rather than performance specifications, the DoD view may eventually include all Configuration Items.
Typically the top tier of Configuration Items directly relate to the line items of a contract and the work breakdown structure. The determination of the need to designate them as Configuration Items is normally simple and straight forward. However, there are many cases in which other lower-level items should also be selected based on requirements of the programme.
Although the initial Configuration Item selection generally occurs early in the acquisition process, its consequences are lasting and affect many aspects of program team activities, systems engineering, acquisition logistics, and configuration management. Configuration Item selection establishes the level of DoD configuration control throughout the system life cycle.
Selecting Configuration Items separates a system into individually identified components for the purpose of development and support. DoD Configuration Item designation should reflect the optimum level for both acquisition and support. During acquisition, this is the level at which a contracting activity specifies, contracts for, and accepts individual components of a system, and at which the logistics activities organise, assign responsibility and report modification and maintenance actions during support.
During the concept exploration and the programme definition and risk reduction phases, the system architecture is established, the program work breakdown structure is developed, and major Configuration Items are selected. These activities provide the basis for the Supportability Plan for the program, which, in turn, dictates the selection of lower-level Configuration Items. Development, acquisition, retrofit, and interfaces are all affected by breakout of the key system elements into Configuration Items during early stages of development efforts.
Many engineering requirements or considerations can influence the selection of Configuration Items. Throughout development and support, the allocation of engineering effort and organisation are rooted in the selection of Configuration Items. Developing contractors should participate in the selection process and provide recommendations based upon engineering or other technical considerations.
Configuration Items selection criteria are applied to contractor recommendations to decide on the items under review by DoD. Decisions to designate specific candidates as Configuration Items and decisions on the time when they will come under DoD control normally involve an integrated team of acquisition programme administration, systems engineering, and acquisition logistics. In addition, the contractor determines those items in the system that are not DoD Configuration Items, but which will be subject to lower tier lower tier configuration .
Typical example for multi-agent package supplier problem is the configuration of telecommunication switches. In this scenario, the final product for the customer—a large-scale telephone switching system—consists of a configurable main switch but also of subcomponents, provided by different suppliers and are themselves configurable.
Many techniques of distributed problem solving have been used e.g., on distributed constraint satisfaction, multi-agent planning or agent-based simulation, but there are not many specifically aiming at developing formulas for solving distributed configuration problems.
New challenges arise for the problem solving phase. Often, the configurators in supply networks are organised in sequential manner. So finding a solution to the overall configuration problem requires not only the definition of communication and agent exchange protocols but also advanced reasoning techniques.
Before trying a value assignment in the search process, each local connection first checks if the variable “belongs” to one of the supplier systems. In such a case, it contacts the supplier configurator and asks for a value. If no value can be found, local backtracking is initiated.
After a variable assignment, the system checks if one of the suppliers has to be informed of the value change. If the new value is not accepted by the supplying system, again backtracking has to take place. Client-server style instructions are in general relatively easy to implement and have—at least in the sketched domains—a good correspondence to the real-world problem setting.
But there are limitations due to their sequential and unfocused backtracking behaviour, which can lead to a high number of messages to be exchanged among the configurators. There are requirements and challenges of modeling and solving distributed configuration problems capability for distributed backtracking in constraint-based approaches.
“Twin” distributed problem solving rules for two application scenarios are used. In both cases, the solution architecture is based on having main configurator that coordinates multiple supplier configurators implementing a defined interface and share parts of their configuration model. One technique developed for the multi-agent market telecommunication switch scenario, is based on forward checking and backtracking.
Must create infrastructure to model and solve a variety of problems from the area of Multi-agent Systems and distributed Artificial Intelligence including distributed resource allocation, scheduling or verification maintenance. Modeling and solving distributed configuration problems, in which several agents jointly and in a loosely coupled, non-parallel manner cooperate in the problem solving process.
Decentralised, event-driven distributed simulation is particularly suitable for modeling systems with inherent uncoupled parallelism, such as agent based systems. However the efﬁcient simulation of multi-agent systems presents particular challenges which are not addressed by standard parallel discrete event simulation models and techniques.
Product configuration can be defined as the task of tailoring a product according to the specific needs of a customer. Due to the inherent complexity of this task, for example includes the consideration of complex constraints or the automatic completion of partial configurations.
Artificial Intelligence techniques have been explored for a long time to tackle such configuration problems. Most of the existing approaches adopt a single-site, centralised approach. In modern supply chain settings, however, the components of a customisable product may themselves be configurable, thus requiring a multi-site, distributed approach.
We have identified challenges of modeling and solving such distributed configuration problems and propose an approach based on Distributed Constraint Satisfaction. In particular, we advocate the use of Generative Constraint Satisfaction for knowledge modeling and show in an experimental evaluation that the use of generic constraints is particularly advantageous also in the distributed problem solving phase.
We present market models for a well-defined class of distributed configuration design problems. Given a design problem, the model defines a computational market to allocate basic resources to agents participating in the design. The result of running these “design markets” constitutes the exchange solution to the original problem.
After defining the configuration design framework, the mapping to computational markets is described. For some simple examples, the system can produce good designs relatively quickly. However, a closer look shows that the design markets are not guaranteed to find optimal designs, and we identify and discuss some of the major pitfalls. Despite known shortcomings and limited explorations thus far, the market model offers a useful conceptual viewpoint for assessments of distributed design problems.
Many conﬁguration systems are centralised and do not allow manufacturers to collaborate on networks for offer-generation or sales-conﬁguration activities. But the integration of conﬁgurable products into the supply-chain of a business requires the cooperation of the various manufacturers’ conﬁguration systems to jointly offer valuable solutions to customers.
As a consequence, there is a need for methods that enable independent specialised agents to compute such conﬁgurations. Several approaches to centralised conﬁguration are based on constraint satisfaction problem solving. Most of them extend traditional constraint satisfaction problem approaches in order to comply to the speciﬁc expressions and hard-to-track requirements of conﬁguration and similar integration of tasks.
The distributed generative constraint satisfaction problem framework proposed here builds on a constraint satisfaction problem construct that encompasses the generative aspect of variable creation and extensible domains of problem variables. It also builds on the distributed constraint satisfaction problem framework, supporting conﬁguration tasks where knowledge is distributed over a set of agents.
Notably, the notions of constraint and service providers are usually generalised, adding an additional level of extending inferences to types of variables. An example application of the new framework describes modiﬁcations to the market signals and our evaluation indicates that the distributed constraint satisfaction problem framework works pretty well.
1. Designating a system component as a Configuration Items increases visibility and control throughout the development and support phases.
2. For system critical or high technical risk components, added visibility can help in meeting specified requirements and maintaining schedules.
3. For each contract, there should be at least one Configuration Items designated for complex systems
4. Major functional design components are usually designated as Configuration Items.
5. The initial selection is normally limited to the major component level of the work breakdown structure.
6. As system design changes during development and complex items are further subdivided into their components, additional Configuration Items may be identified.
7. Developing contractors should be given maximum latitude to design below the system level.
8. Changing system architecture or the reallocation of functions after a baseline has been established by DoD is best avoided
9. Each Configuration Item should represent a separable entity that implements at least one end use function.
10. The selection of Configuration Items should reflect a high degree of independence among items at the same level.
11. Subordinate components are recommended as Configuration Items during the detail design process, should all be functionally interrelated.
12. The complexity of Configuration Item interfaces in a system should be minimised.
13. Complexity of Configuration Item often results in increased risk and cost.
14. All subassemblies of a Configuration Item should have common mission, installation and deployment requirements.
15. For systems with common components, subsystems, or support equipment, each common item should be separately designated as a Configuration Item at an assembly level common to both systems.
16. A unique component specific to only one of multiple similar systems should be identified as a separate Configuration Item of that system.
17. Factors to consider include the extent of the modification; the criticality of the modified Configuration Item to the mission of the system
18. Extent of ownership, Configuration Item documentation required and available to DoD
19. Would Configuration Item designation enhance the required level of control and verification of these capabilities?
20. Will the Configuration Item require development of a new design or a significant modification to an existing design?
21. Does Configuration Item have a separate interface with item developed under another contract?
22. Does the Configuration Item have a separate interface with an item controlled by another design activity?
23. Will it be necessary to have an accurate record of Configuration Item exact configuration and the status of changes to it during its life cycle?
24. Can or must the Configuration Item be independently tested?
25. Is Configuration Item required for logistics support?
26. Does Configuration Item have the potential to be designated for separate procurement?
27. Have different activities have been identified to provide logistics support different parts of the system?
28. Does Configuration Item have separate mission, training, test, maintenance and support functions, or require separately designated versions for such purposes?
29. Do all subassemblies of the Configuration Item have common mission, installation and deployment requirements, common testing and DoD acceptance?
30. Are performance or design verification demonstration, system integration and testing, activities usually accomplished for each of the selected Configuration Item ?
31. Technical reviews and budget allocations activities usually accomplished for each of Configuration Items selected.
32. The number of Configuration Item selected will determine the number of separate meetings related to the overall activity
33. Number of Configuration Item may lead to delays in completing critical development and support milestones.
34. Existing Configuration Item available from inventory may be modified and designated as a separate and different configuration of that item to save time and money.
35. Factors to be traded off include complexity, the use of new materials, processes, and the insertion of new technology.
36. There are no rules to dictate the optimum number of Configuration Item for a given system, but the fewer items, the better. Selecting too many items increases development and support costs.
37. Each Configuration Item to be developed comes with an associated set of technical reviews, performance or design verification demonstrations, formal unit and integration tests, and documentation requirements.
38. Activities adds an increment of development cost and also adds costs for storage and upkeep of information related to the activities
39. Many Configuration Item interfaces to be defined-- if they are all baselined early to limit contractor freedom to develop design solution, solve problems expeditiously, and implement advantageous changes without contractual consequences.
40. Configuration Item functionality defined at too low a level or including unnecessary design constraints requires formal test, and technical reviews, beyond what is required achieve reasonable assurance of system performance.
41. Problems may arise if performance specifications for the lower-level Configuration Item are baselined too early
42. Increased overall number of requirements in the documentation disproportionate to the unique technical content of the requirements
43. Excessive Configuration Item fragmentation decreases visibility of system performance and increases the overall volume of requirements
44. Configuration Item fragmentation complicates update review, approval, and control process.
45. Consequences of having too few Configuration Items include Increased complexity of each item resulting in decreased insight and ability to assess progress
46. Where the lowest level designated Configuration Item is a complex item implementing unrelated functions, potential for reuse of the item/portions is diminished
47. Re-procurement of Configuration Item and components is complicated with few sources are limited making testing of critical capabilities more difficult.
48. The inability to account for the deployment of a Configuration Item , whose component parts are disbursed to different locations
49. Difficulty in addressing the efficacy of changes and retrofit actions when different Configuration Item quantities or separately deliverable components
50. Increased complexity in accounting for common assemblies Configuration Item and components by the contractor