Introduction
The process of deregulation and privatisation of the electric utility industry is in an advanced stage in many developed countries. In order to survive, the affected utilities were forced to find ways to be more cost effective. Geo-spatial Information Technology (AM/FM/GIS) is being successfully implemented as integrating technology by many utilities to stay competitive. AM/FM/GIS systems reduce data duplication and increase data integrity. In the past a lot of energy was wasted by searching for data and verifying the accuracy thereof.

The trend of deregulation and privatisation is reaching developing countries, forcing electric utilities to change the way in which they do business. Similar to the developed world, AM/FM/GIS has been identified as a cost cutting tool to create more effective utilities. There is at least one additional challenge in implementing AM/FM/GIS in the developing world. Most of the utilities form part of government structures, which are cash strapped and often adverse to capital spending. At first AM/FM/GIS is perceived as far too expensive, given the unfavourable foreign exchange rates. However, after careful analysis it is clear that AM/FM/GIS can realise many more benefits than the cost of implementation.

These utilities are in desperate need of properly motivated capital programs in order to source the necessary capital funding. This implies that a comprehensive long term network plan is needed. This paper focuses on the long term network planning process and how this planning is performed on a AM/FM/GIS system.

Network planning process
This section provides an overview of the network planning process employed by many electric utility companies in developing countries.

The need for long term Network Planning
Any business that wants to survive into the future has to perform long term planning. In the electric utility industry this means that a network has to be planned to meet the anticipated future demand in the most cost effective way.

Electrical networks are capital intensive and with capital being scarce, the network extensions need to be motivated properly by funding organisations. An additional spin off of proper long term planning is that tariff changes can be planned and phased in gradually. Finally, a utility with a strategic plan has a better chance of being successful in a more competitive future.

Process followed
The power system planning process refers to the engineering exercise that network planners follow to ensure that the preferred power system is established in the long term.

The following characteristics are considered to be essential for a power system:

The combination of costs to the utility due to capital expenditure and the cost to the customer due to power failures should be minimised.
Rated voltages of the system should be aligned with quality equipment from a wide range of manufacturers in an industry where healthy competition prevails.
Network capacity allocation must be provided as close to the electrical load centres as possible in a fashion such that reserve capacity is minimised, but is still within acceptable reliability requirements.
Facilities must fulfill the electrical energy requirements of the society and the business that they serve at a cost that the users can afford.
Electrical energy losses must be minimised.
Facilities must comply with environmental constraints.

The process requires participation of all the major role players and the results must conform to the needs of the customers served. The process is practical and followed by many organisations or individuals before major capital expenditure is incurred. Strategic planning is an essential prerequisite to the success of any business. Businesses or economies that excel globally are characterised by sound strategic planning on a continuous basis.

The strategic plan also serves as a basis for project planning. The availability of such a plan simplifies project planning for all disciplines. It is however important to revise the strategic plan on a regular basis in order to accomodate changing external influences to which future planning must react and adapt. Both annual and medium term project planning is far simpler with a long term strategic plan in place.

The flow diagram in Figure 1 depicts the main steps of the planning process. The process starts with various supporting tasks that are performed to gather relevant planning data, determine refurbishment needs and obtain strategic long term inputs regarding land use, demographic and economic studies.

Figure 1: Network Planning Process

With relevant data and strategic inputs available the geographical load forecast is performed for the complete electrical supply area. Both the load forecast and identified network refurbishment needs are used as inputs to identify network development alternatives. These alternatives are evaluated technically by performing load flow, fault level and reliability analyses. The technically sound alternatives are evaluated financially before they are finally checked against the planning criteria.

The chosen alternative is documented as the preferred alternative that forms the strategic development plan.

Integration Issues and Constraints
Historically the steps mentioned in the previous paragraph were performed separately. Applications / databases were developed to support these activities. These applications were mainly developed to operate as stand alone modules, quite often with closed databases, limiting the interfacing and integration possibilities without major software redesigns.

What is needed is an integrating technology that can form a platform for customised functionality development based on one data set. This technology must also cater to integration with existing legacy systems.

Network planning utilising AM/FM/GIS
In order to integrate existing legacy systems and to open access to multiple data sets and complex functionalities, most leading utilities throughout the world today implement Geo-spatial Information Technology (AM/FM/GIS). By providing a realistic model of the "real world objects", AM/FM/GIS offers an environment for the efficient support of day to day functions of planning, constructing and maintaining a network. It combines "background" data such as simple vector or raster maps with structured/topological "foreground" network elements. The system thus computerises technical information and is designed to take the network through the planning stage up to the AS BUILT stage.

Utilising Legacy Systems
Many utilities have legacy systems in place that perform mission critical functions. It would be too costly and risky to replace all these systems. As integrating technology, AM/FM/GIS is used to pull these systems closer together.

The AM/FM/GIS system is designed with the holistic utility process in mind. Where existing systems are in place, the AM/FM/GIS system interfaces with these systems. These interfaces are at various levels of detail. Legacy systems with an open database are linked actively to the AM/FM/GIS system. If possible, referential integrity between the two systems is applied.

In the realistic environment a substantial number of legacy systems have proprietary databases with very limited interfacing possibilities. In such cases data exchange is done by means of a text file. More often than not no data can be imported into these legacy systems. These "closed" legacy systems are the first to be replaced by appropriate functionality within the AM/FM/GIS system. This approach ensures increasing data integrity and less room for human error.

Integrating the Planning Functions
Anybody who has been involved in proper long term strategic planning knows that the process depicted in Figure 1 is a substantial amount of work. Even with the help of tailor made applications / databases for a number of the process steps, a major effort is required to maintain data integrity between the various databases.

The implementation of AM/FM/GIS addressed the above mentioned problem and in addition created at least two other major benefits.

Integrating the planning functions into one data model ensures that changes in one area are available to other applications.For instance, the load forecast is automatically available to any load flow study, combined customer damage function or calculation of a load duration curve. This means that the planning information that is needed is available - no need for export and import routines.

Another advantage of the AM/FM/GIS system is that town and regional planning data is imported and used directly as input to the load forecast. Although the AM/FM/GIS system might not hold the master data set of town and regional planning, all their information is now at the disposal of the electrical network planner. This increases the quality of the long term network plan because the load growth is based on proper land use projections.

A major advantage of the AM/FM/GIS environment for a network planner is version management. A long term network planning study takes time, and for this reason it would be fatal to lock out the section of network on which a planner is busy. Version management ensures that the planner's colleagues can use the system while he/she works on a portion of the network.

An AM/FM/GIS integrated planning environment saves the planner a lot of effort by reducing duplication and improving data integrity. This allows the planner to do what he/she should be doing, namely to study different scenarios in order to identify the most cost effective network development plan.

Applications developed within AM/FM/GIS

The following applications are examples of planning tools developed to operate within the AM/FM/GIS system:

Routine to import stand data from a legacy GIS.
"Network Constructor" to assist the user with the creating of substation single line diagrams.
Geographical Load Forecast (GLF) for long term load forecasting.
Network Analysis Functions to interface to load flow, fault level and reliability analysis tools.

Additional Benefits
The previous paragraph illustrates the direct benefits of an AM/FM/GIS system to the network planner in fulfilling his/her role in the business. Instead of spending most of his/her time searching for data, he/she can focus on the planning aspects and produce a better strategic plan.

By spending more time and effort on detail network analysis, the capital expenditure on the network is optimised. Utilising state of the art network reliability analysis applications, the most effective solution for each scenario is determined. The utility cost is weighed up against the customer damage cost to determine a value based planning solution that is in the best interest of the wider community. In one specific case in South Africa, the utility was used to build new substations according to a certain high standard. A reliability analysis study indicated that for many scenarios these substations were heavily over designed. By applying the value based planning approach at least 15% of the capital budget could be saved in this case. These savings alone were far more than the cost of implementing AM/FM/GIS.

Another spin-off for the utility is that AM/FM/GIS enables wider access to the utility data set(s). By means of web-servers and standard viewers a wide range of employees, contractors and even customers can get access to the utility data.

Challenges for Version Management
The day to day changes to a network can be handled perfectly by version management. These changes are typically the building and commissioning of new substations, the re-routing of cables and the replacement of switchgear.

Long term planning adds another dimension to the requirements of a planning system. The network planner wants to be able to view, evaluate and analyse ANY one particular year, up to 20 years into the future. Creating 20 different alternatives of the network is no solution because any change in future timing or network phasing would imply changes in at least two different alternatives.

The above mentioned issue was resolved by providing each network component with a commissioning and decommissioning date. Hereby the planning alternatives are reduced drastically and the planner can view, evaluate and analyse the network for any specified date.

Another challenge that was faced was the question of standard libraries. For network analysis standard line and transformer parameter libraries are used to calculate the line, cable and transformer impedances. Similarly a standard cost library is used as input for capital extension costs. When these libraries are version managed, any new standard items added in a sub-alternative will not be available to higher alternatives. The suggested solution is to keep standard libraries separate to the version managed data set.

Conclusion
Geospatial Information Technology fits like a glove in the long term network planning environment. At long last the technologies of version management and long transactions enable a planning department to operated in a truly integrated environment without unnecessary duplication of data and effort.

The implementation of AM/FM/GIS systems in Southern Africa proves that, although these systems are expensive in the developing world, they are adding value by increasing the cost effectiveness of utilities.