The APDM is in a stage of minor enhancements and refinements. The lion’s share of the development work is complete for the model. Currently, development of the model is focusing on improving the ‘Core Elements’ and the ‘Conceptual Classes’ of the model to handle complex data modeling tasks, and to perform with ESRI’s latest release of ArcGIS Version 9.0.
The APDM is a geodatabase model that was developed for implementing transmission (gas and liquid) pipelines. At each stage of model development a standard set of justifications or design rationale were used as a litmus test for validating the progress of the APDM. These justifications served as guidelines for ensuring the model met the needs of the pipeline industry. Each justification describes some of the considerations and background material that were measured and weighed to determine the final model. The APDM was developed jointly by the ESRI Pipeline Interest Group steering and technical committees. The core elements of the APDM were derived from the ISAT, PODS, and ISPDM models. Every attempt was made to make the APDM open to data transfer between each model. The steering and technical committees strove to balance the interests of each pipeline model group, the pipeline operators, and the pipeline vendor community. Participation in both committees was divided between operator and vendor communities and ISAT/PODS data model members.
Design Rationale and Model Development
The APDM is intended to be a template, not a standard. There is no governing organization that has officially approved the APDM as a standard. The features and relationships in the model were determined to be critical or common to 80 percent of all pipeline companies’ typical implementations of geographic information system technology. The APDM, similar to most other published models on the ESRI Web site, represents core features found in almost every pipeline system. The intent of the model was never to create a database standard, but rather to create a database template, from which custom models could be created and evolved. However, one of the design criteria of the model was to create and delineate core elements of the model that must be maintained in order to preserve a standard for data transfer, application development, and conversion efforts between APDM implementations. It is important to realize that no single pipeline data model can do everything for all organizations. Realizing the variation in how data is modeled between different pipeline companies, the technical committee developed the APDM according to four guiding principles. The APDM is designed to provide a set of core elements that will remain consistent for any APDM implementation. The core elements are designed to ease data transfer between existing pipeline data models and for the development of portable APDM applications by third party vendors. The APDM will provide a mechanism for locating features on or along the pipeline centerline by both absolute positioning and by linear referencing (commonly referred to as stationing). It is not the purpose of the APDM to prescribe the approach to any implementation for the model. These features can exist as geometric features in feature classes, dynamic events in event tables, or a combination of both. Features (or tables or objects) will be included in the APDM if they are required by 80 percent of all pipeline companies, and if they are required by United States government regulatory agencies. The APDM can be implemented and maintained within a geodatabase without the need for custom application code. Below is a brief chronology of the model’s development.
- March 2002 – M.J. Harden Associates Inc. starts the work on the original model.
- July 2002 – The model is presented at the ESRI User Conference in San Diego, California. An open invitation to participate in the design of the model is extended to the pipeline community.
- August 2002—The initial meeting of interested member groups occurs at ESRI, Redlands, California.
- October 2002—The steering and technical committees are officially formed at the ESRI Electric/Gas Utility User Group Conference (EGUG), Coeur d’Alene, Idaho.
- December 2002–June 2003—Monthly technical and steering committee meetings at various member organizations. Development of intellectual property agreement, steering committee charter, technical committee mandate, operational procedures, and APDM content and structure.
- March 2003—The APDM is released for public comment at the ESRI (Petroleum Users Group) PUG meeting, Houston, Texas.
- July 2003 – APDM 1.0 released
- October 2003 APDM 2.0 released
- August 2004 – APDM Version 3.0 released.
- February 2008 – APDM 4.0 released
- November 2011 – APDM 5.0 released
- March 2014 – APDM 6.0 released