CM Overview
CM is the practice of handling changes systematically so that a system maintains its integrity over time. CM involves the policies, procedures, techniques, and tools to: manage, evaluate proposed changes, track the status of changes, and to maintain an inventory of system and support documents as the system changes. CM programs and plans provide the technical and administrative direction to the development and implementation the procedures, functions, services, tools, processes, and resources that are required for successful development and support of a traffic management center (TMC).
In cases of subsystem or system development, CM allows TMS management to track requirements throughout the life cycle through acceptance and operations and maintenance. As changes are inevitably made to the requirements and design, they must be approved and documented, creating an accurate record of the status of the system. The CM process may be (and ideally should be) applied throughout the system life cycle.
CM Process
The general CM process is described graphically in figure 1. While not shown in figure 1, a CM plan is integral to the process. The CM plan is the document that will guide the CM program of a particular group. Plans typically are established at the outset of the CM program and undergo changes as the system evolves and as areas where the plan can be improved are identified. Contractors, in conjunction with the particular agency that will be using the CM program, often develop the plans. The benefit of the CM plan is that it provides a central location for all CM program information.
Figure 1. Configuration Management Process
D Configuration Identification
Configuration identification refers to the activities and processes dedicated to creating and maintaining full documentation describing configuration items. The goal of configuration identification is to provide a unique identifier for each item to help track the changes to that item and to be able to understand its place in the system. Often, identification involves recording the identifier, maintenance history, relevant documents and other information that will simplify the change process in the future. Configuration identification may be defined as anything that has a function in the TMS. Therefore, system components classified in the broad categories of software, cabling, and hardware are considered as configuration items, in addition to system requirement and design documentation.
Configuration identification includes processes such as item naming, drawing and document management, information management and baselining. Configuration identification is the first and possibly most time-consuming process in CM, and if done correctly, will result in significant long-term benefits.
The items selected for configuration identification depend upon the scope of the effort. For example, configuration identification may be constrained to software items or may be larger and include system level components ranging from software, hardware, firmware, documentation, and perhaps the CM plan. The plan serves as the primary resource for any questions pertaining to the CM program. The benefits of configuration identification are to provide a means of unique identification of system components to support traceability and change management processes. Proper identification minimizes confusion over various versions of configuration items and facilitates the change control process by allowing items to be more easily tracked as they undergo change.
Change Management/Change Control
Change management, or change control, is the process of assessing the impact of a possible change to a system, determining the fate of the proposed change, executing the approved changes, and ensuring that the change is carried through to the proper documentation. Usually, a change is proposed by someone who is working with the particular part of the system that will be changed. Change requests are submitted to the relevant administrative body for review. This body is normally referred to as a change control board (CCB). The CCB will review the proposed change, determine its effect on the overall system and decide whether or not to proceed with it. An important part of change control is ensuring that the change itself is documented and that the relevant configuration item's (CI) documentation now reflects that change.
The primary benefit of an effective change control procedure is that proposed changes are evaluated in terms of their impact on the entire system. Change control allows the changes to be reviewed by personnel with a variety of interests and areas of specialty. This minimizes the negative impacts of changes on other components of the system. Change control also ensures that the changes are properly implemented and within schedule and cost constraints.
Configuration Status Accounting
Configuration status accounting (CSA) is the process of ensuring that all of the relevant information about an item – documentation and change history – is up to date and as detailed as necessary. A primary goal of CSA is to repose CI information necessary to support existing and future change control efforts. A typical CSA system involves establishing and maintaining documentation for the entire life cycle of an object. Status Accounting is ideally carried out in conjunction with change control.
The primary benefit of CSA is that it provides a methodology for updating all relevant documentation to ensure that the most current configuration is reflected in the configuration identification database. CSA accounts for the current status of all proposed and approved changes. The goal of CSA is to provide decision makers with the most up-to-date information possible. Having the most recent information about a CI or changes implemented for a CI helps to reduce research efforts in future change control activities whether implementing a new change or rolling back a change that had a negative or unexpected impact.
Configuration Audits
Configuration verification and audit is the process of analyzing configuration items and their respective documentation to ensure that the documentation reflects the current situation. Essentially, 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 most important goal of this process is to prevent lost time on future changes due to inaccurate documentation. If discrepancies are located between the documentation and the item, the personnel carrying out the audit will prescribe a course of action for remedying the problem.
The most important benefits of configuration audits are that they verify that changes were carried out as approved by the relevant administrative body and that documentation about an item reflects the current configuration. By ensuring that changes are properly executed and all documentation is updated, configuration audits will facilitate future changes to the system.
CM Implementation
As with any new initiative, a CM program must have a champion to spearhead its initiation. Sometimes, the champion faces a difficult battle, particularly due to cultural resistance within the agency. CM often is viewed as an expensive bureaucratic process with benefits that are hard to quantify. For this reason, the champion must educate decision makers and system staff on what CM is, and isn't, as well as describe the benefits of CM in a tangible manner. The champion must also secure funds or staff time to use in creating a CM plan for the program.
Once initial buy-in has been established, the next step is to create a CM plan. Depending on the complexity of the system, the plan may be developed in-house or by a consultant. Regardless of the developer, the agency must be actively involved in the entire plan development process. Once the plan is developed, the blueprint is in place to drive the program. The champion must make it clear to decision makers that the creation of the plan is but the first step in the program. Committing to CM means a long-term staff, budget and procedural commitment.
CM Administration
The success of CM is solely dependent on how well an agency organizes itself to institute the required policies and processes. Depending on the size of the system and complexity of the CM program, the CM administration may be comprised of a large or small group of individuals. Regardless of the administration's size, the roles of each individual within the CM administration must be well understood. The CM plan should specify the responsibilities of each person involved in the CM decision-making process. In order for the CM program to be as effective as possible, it is ideal to include personnel from across the spectrum of departments, such as planning, management, technical/design, operations and maintenance, and financial. Doing so ensures that no areas are overlooked during the application of the CM program and reduces the chances of the CM activities of one group overlapping or conflicting with those of another.
Additionally, effective CM administration starts at the top. The TMS facility/system manager must play an active role in the CM program. In most cases this individual serves on the CCB and, in some cases, serves as the CM manager. In all cases, the TMS facility/system manager must fully support the program and become involved on critical change decisions.
