10. Configuration Management
It is unrealistic to assume that the environment in which the ICMS concepts and requirements are developed, and in which the system is subsequently deployed, integrated, and operated, will not change. The nature of complex systems is that change is inevitable, whether it be institutional, operational, or technical in nature. What is essential is to manage and control the change processes through "configuration management."
Configuration management (CM) is a part of the entire systems engineering process - a cross-cutting element throughout the life of any system. CM provides a holistic approach for effectively controlling system change. It helps to ensure that any proposed changes to the operational concepts, requirements, subsystems, the network systems within the corridor, and the response plans, including their associated documentation, are considered in terms of the entire ICM program and ICMS, minimizing adverse effects. Configuration management includes standardized procedures and techniques that allow the corridor stakeholders to propose changes, evaluate the impacts of proposed changes, and then to track, verify, and document those changes that are made.
A complete CM program includes provisions for the storing, tracking and updating of all information and documentation on a component, subsystem and system (network and corridor) basis. This provides corridor stakeholders with an up-to-date baseline of the ICMS. Configuration management has two fundamental purposes: to establish system integrity, ensuring that system documentation accurately describes and controls the functional and physical characteristics of the ICMS, and to maintain system integrity by synchronizing any changes to the system with this documentation. This also results in a working baseline that is always available to implement and provide transportation management services within the corridor.
The configuration management process is described in more detail in the document "Configuration Management (CM) for Transportation Management Systems" (Reference 6), which includes Figure 10-1 as a graphical description of the CM process. Key activities are summarized below.
Figure 10-1. Configuration Management Process8
- CM plan: While not shown in Figure 10-1, a CM plan is integral to the process. The CM plan is the document that guides the CM program for a particular project. This plan should be incorporated into the SEMP and program plan.
- Configuration identification. This refers to the activities and processes dedicated to creating and maintaining full documentation describing configuration items (CI). A CI is defined as anything that has a function in the ICMS. The goal of configuration identification is to provide a unique identifier to each item to help track the changes to that item and to be able to understand its place in the system.
- Change management. This is process, sometimes referred to as Change Control, by which the need for a change is identified, the impact of the change on the system (i.e., cost, schedule, operational performance) is analyzed, the proposed change is evaluated by a review body of corridor stakeholders and, if approved, the approved change is incorporated into the ICMS and / or existing network system with its appropriate documentation.
- Configuration status accounting This is record keeping and reporting function of the configuration management process, ensuring that all of the relevant information about an item, particularly the documentation and change history, is up to date and as detailed as necessary.
- Configuration audits This is a process of analyzing Configuration Items and their respective documentation to verify and ensure that the documentation reflects the current situation. In essence, while Change Control ensures that change is being carried out in adherence with the CM Plan, Configuration Audits ensure that the change was appropriately carried out.
The CM process should be applied throughout the ICMS life cycle. This allows the corridor stakeholders and ICMS managers to track objectives and requirements through ICMS design, integration, acceptance and operations and maintenance. As changes are inevitably made to the operational concepts, requirements and design, they must be approved and documented, creating an accurate record of the status of the system. The CM process should also be applied to the network systems that comprise the ICMS, thereby ensuring that the network agencies and stakeholders consult with one another before making any changes to their respective systems, and then thoroughly documenting the changes, however routine they may seem to be.
8 "Configuration Management for Transportation Management Systems," 2003 (Available from the TMC Pooled Fund Study website http://tmcpfs.ops.fhwa.dot.gov).