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Procurement: Long lead items pose a real problem for the buyers as availability will vary according to the equipment manufacturer capacity, or specifications may be compromised in order to achieve a favourable price and delivery!

At this stage we have evaluated all the aspects that need to be taken into consideration. The evaluation has concluded that a modular approach to the design in conjunction with streamlining related activities will form the basis of the way forward.

It can be very tempting and indeed looking at some of the promotional videos for today Substation Cad systems one could be forgiven for thinking that moving to a 3D environment can be achieved by simply replicating the existing 2D engineering standards. I concede the fact that some efficiency can be gained in both time and resources but if done from a wider perspective a greater efficiency can be achieved. More on this in later posts!

The main subject of this article is Procurement and how the evolution to 3D impacts the purchase and decisions relating particularly to Long-Lead items.

masthead_product_substation

Long lead items of equipment may include units like Transformers and High Voltage Circuit Breakers. These types of equipment are usually purchased well in advance of the start of the actual design process, sometimes with lead times as long as a year.

  • These are complex pieces of kit and occasionally vary in configuration according to selected manufacturer and cost. Though the specification may comply with the requisite TBA and CBA approvals the physical configuration may need to be evaluated as part of a Design Review process for potential implications on station layout and design. So there will need to be a design input at this early stage as it would be improper for these decisions to be left solely with the Procurement team.

For the Transformers this should not be a major problem on account of these items usually being physically isolated from the main switchyards and breaker areas. However the latter; Circuit Breakers; will need to considered carefully as any major configuration change will have an impact on design standards.

modulares-design

I should say at this time that the 3D Cad models are prepared from existing standards incorporating historical component assemblies in a modular format…but as I said I will go into that later. The main benefit is that the Basic Design team can evaluate equipment specification and configuration against a library of the most common type of assemblies very quickly and if necessary adjust the scheduled design time for equipment that is essentially “non-standard”.

  • The other implication is forward planning. At the time of this development the projects were planned ahead of time to account for long lead item purchasing and resources based on historical planning data. The realization that the 3D method could reduce the average design schedule by 60% it then followed that some major changes will be required with the planning process to account for this. The main issue is lack of historical data working with 3D methods.

It was decided that constant evaluation of design actual against perceived times would be constantly evaluated to develop the necessary historical data. Due to there being an existing backlog of work it transpires that maintenance and upgrade projects could be incorporated to fill in the gaps when considerable time was saved. The other aspect relating to proper TBA and CBA consultation has not been done adequately in the past and now should not be detrimental to achieving these goals.

As a footnote to this we are basing our achievable goals on a 60% reduction in average project time. As an example of what could be done I presented a solution for a new extension to an existing substation including fully detailed BOMs and deliverable drawings in only 6 days (somewhere close to an 80% time reduction). On this occasion this was seen as nervada, however this was only achievable due to my experience with 3d cad and work processes. I would not expect their engineers to achieve this level of productivity in the short term but 60% would be achievable.

It is quite clear though that as the engineers gain experience then projects will be done very quickly and this has to be factored into and evaluated frequently to maintain accurate forecasting.

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