The concept design requires, as a minimum, the following data and design information for the proposed production facility:

	A process flow diagram
	Heat and Material Balance
	An equipment list (layouts cost estimates)
	Selection of major items of equipment
	Size and cost of major items of equipment

The Concept design includes the project cost, duration and identifies risks and how to minimise these.

A concept is robust if it does not require changes during the Front End Engineering and Detailed Design stages. This requires the development and evaluation of a number of competing concepts which would meet the project specifications but with differing costs, operational flexibility, reliability and plant availability.

For example a gas compression facility can be designed with reciprocating compressors driven by gas engines; or alternatively by centrifugal compressors driven by gas turbines; or driven by electric motors. Similarly the motors could be fixed speed drive or variable speed drives. The cost and availability of the resulting concepts would be very different and would require careful evaluation of their pros and cons.

To ensure that the selected concept meets the project objectives and specifications, it is necessary to verify the concept design. It is normal practice to carry out a Reliability and Availability analysis of the concepts using "RAM models" using statistical data analysis. These statistical models use reliability and availability data of the selected equipment from generally published information and from equipment suppliers. The drawback of this approach is that the major equipment, such as large compressors and drivers, which have the greatest impact on plant availability, are of a bespoke design and the reliability and availability data is usually obtained from the equipment suppliers. The source of this data is confidential and "selective" and cannot be verified independently. The reliability values of machinery selected for RAM analysis have a great impact on the overall plant availability .

MSE has developed an alternative approach based on "deterministic models" which use our in-house performance and reliability data of major items of machinery. The mathematical models examine the knock on impact of machinery failures on system performance and system capacity, thus providing a more realistic plant performance and system availability.

For example using statistical models, the production capacity of a compression plant based on two compressor trains would be halved if one train fails. Using MSE model for the same plant, the failure of one train resulted in only 10% loss in production capacity instead of 50% production loss. This is because MSE model may take into account the impact of the loss of one train on the overall process systems and determined real production capacity with the revised data. MSE Concept design provided higher performance and capacity while using realistic performance and availability data.

MSE verifies the concept design by building steady state models (GASMAN) which include the processing facility, heavy machinery, and export pipelines. Where necessary, MSE extends the model to include the upstream system, including gas gathering system, well and wellheads and gas reservoirs. The GASMAN model allows the project specification to be verified for normal operation as well as for off-design operation; for example, during project start, where operating conditions differ from the design specification, as well as during early life.

Project specifications include reservoir predictions which are subject to uncertainties in terms of product compositions, pressures, flows temperatures etc. The GASMAN model verifies the upstream sensitivities and their impact on the process design resulting in a more robust concept.