Configuration Control
OVERVIEW
Configuration control is perhaps the most visible element of configuration management. It is the process used to manage preparation, justification, evaluation, coordination, disposition, and implementation of proposed engineering changes and deviations to effected configuration items (CIs) and baselined configuration documentation.
The primary objective of configuration control is to establish and maintain a systematic change management process that regulates life-cycle costs, and:
- Allows optimum design and development latitude with the appropriate degree and depth of configuration change control procedures during the life cycle of a system/CI
- Provides efficient processing and implementation of configuration changes that maintain or enhance operational readiness, supportability, interchangeability, and interoperability
- Ensures complete, accurate, and timely changes to configuration documentation maintained under appropriate configuration control authority
- Eliminates unnecessary change proliferation
THE PROCESS OF CONFIGURATION CONTROL
The span of configuration control begins once the first configuration document is approved and baselined. This normally occurs when the functional configuration baseline (referred to as the requirements baseline in EIA/IS-649) is established for a system or configuration item. At that point, change management procedures are employed to systematically evaluate each proposed engineering change or requested deviation to baselined documentation; to assess the total change impact (including costs) through coordination with affected functional activities; to disposition the change or deviation and provide timely approval or disapproval; and to ensure timely implementation of approved changes by both parties. Configuration control is an essential discipline throughout the program life cycle.
Through the configuration control process, the full impact of proposed engineering changes and deviations is identified and accounted for in their implementation. The configuration control process evolves from a less formal process in the early phases of a program to a very disciplined and formal process during the System Development and Demonstration, Production and Deployment, and Operation and Support phases. In the Concept Exploration phase, the configuration control process is employed in support of systems engineering to make sure that the correct version of documents, which communicate technical decisions or definition of pertinent study parameters, is disseminated and used by all personnel. In addition, the process makes affected parties aware that a change is being developed and enables them to provide pertinent input.
In the Concept and Technology Development phase (if applicable ), when the program definition documents are being developed, the configuration control process is also less formal. As part of the systems engineering control process in this phase, there may be several requirements definition baselines established for convenience to ensure that all program participants are "on the same page." A configuration control procedure is helpful in this phase for the review and coordination of changes to the evolving system-level specifications. It provides:
- The identification, documentation, dissemination , and review of changes
- Appropriate versioning of files and revision of documents
- A release process to ensure that each revision or version reflects the applicable changes
During the System Development and Demonstration, Production and Deployment, and Operation and Support phases, a formal configuration control process is essential. The informal document change control that was practiced during concept explorations is insufficient for systems acquisition and sustainment. As the product is being developed and produced, configuration control focuses on the documentation defining performance, physical and functional characteristics, and the configuration of the product.
Configuration control is a management process that uses configuration baselines as references for managing change. Within this context, however, there are several configuration control complexity levels. When viewed at the macro level, the process:
- Addresses the baseline documentation
- Determines which documents are impacted
- Proposes a change covering the impacts to all affected elements
- States when, where, and by whom the documentation will be updated and the change will be incorporated in the product and in all supporting elements
While this top-level macro view appears simple and straightforward, a micro-level view of the configuration control process can be considerably more complex. The micro view reveals the process layer dealing with what must be done to change each affected element, and thus with a wide variety of considerations such as data rights; approval authority, document custodians; design, release, production, installation, and testing organizations; and contractual and interface relationships.
ENGINEERING CHANGE PROPOSAL
An Engineering Change Proposal (ECP) is the management tool used to propose a configuration change to a CI and its baselined performance requirements and configuration documentation. See Appendix B for a sample ECP. Please note that the following discussion describes the procedure for filling out this form. The ECP consists of the items listed in Table 5.1.
ECP Justification Codes:
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ECP Types and Their Function:
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ECP Priorities:
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ECP Content:
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Request for Deviation
A deviation is a specific written authorization to depart from a particular requirement(s) of an item's current approved configuration documentation for a specific number of units or a specified period of time. It differs from an engineering change in that a deviation does not effect a change to a configuration document.
Requests for Deviation (RFDs) are submitted if during design and development, it is determined that for a valid reason (such as long leadtime) a required performance attribute will not be met or verified before scheduled delivery of a limited number of production units.
RFDs are classified by their originators as either minor, major, or critical :
- Critical. The deviation consists of a departure involving safety or when the configuration documentation defining the requirements for the item classifies defects in requirements and the deviations consist of a departure from a requirement classified as critical.
- Major. The deviation consists of a departure involving:
- Performance
- Interchangeability, reliability, survivability , maintainability, or durability of the item or its repair parts
- Health
- Effective use or operation
- Weight and size
- Appearance (when a factor)
- When the configuration documentation defining the requirements for the item classifies defects in requirements and the deviations consist of a departure from a requirement classified as major
- Minor. The deviation consists of a departure that does not involve any of the factors listed as critical or major, or when the configuration documentation defining the requirements for the item classifies defects in requirements and the deviations consist of a departure from a requirement classified as minor.
RFD Contents
The data content of an RFD consists of:
- Submittal date of the RFD or RFD Revision
- Originator name and address
- Identifier of the CI or CSCI for which RFD is being submitted
- The system or top-level CI designation
- RFD identifier assigned by the originator
- Brief descriptive title for the RFD
- CI(s) affected by the RFD
- Description of deviation
- Need for deviation
- Effect on integrated logistics
- Other system or configuration items affected
- Corrective action taken to prevent future recurrence of the nonconformance
- Effect on delivery schedule
- Cost/price consideration
SUMMARY
This chapter provides a close look at the elements of information required to manage the process of change using a configuration management methodology. By now it should be quite clear that anything carrying the CM "flag" must be fully documented and tracked throughout its life cycle.
REFERENCES
This chapter is based on the following report: MIL-HDBK-61A(SE), February 7, 2001 , Military Handbook: Configuration Management Guidance .