Control Engineering

A QDS Systems Quality Solution
November 27, 2007

Well, we had a busy two weeks preparing the public works director's requested proposal to complete the project. Recall there was the Phase II install and control panel construction contract that had never been let, preventing the other three phases of the project from proceeding (Phase I - RTU/HMI supplier, Phase III - Master SCADA, software and project management and Phase IV - communications system).

There were issues with the original scope of the Phase II project. Without getting into the details as to why, the scope had drifted out of sync with the needs of the department. So we got with the City's supervisor of pump station electrical and controls and visited about 20 of the 38 sites over a three day period, which represented every type of layout and special case we might encounter in upgrading the stations. Based upon this we came up with a list of additions, deletions and changes that were needed from the original scope. At all times we kept an eye toward our budget, which was targeted to stay within the original 2004 bid price (recall Phase II had been bid and awarded in 2004. Due to delay of almost two years before a notice to proceed could be issued, however, the contractor requested a significant change order (~$375K) that they and the City never came to terms on).

If this whole story doesn't convince someone that breaking a major municipal project into 4 contracts is a mistake, I don't know what will! The administration and coordination (and you will see waste) is tremendous.

I am happy to say we met our target budget, and submitted our proposal just before the Thanksgiving holidays to the public works director. More importantly, we were able to provide all the original functionality plus some lagniappe (that Louisianian for "baker's dozen"), providing additional functionality beyond the original Phase II scope, thus accomplishing more with the available dollars.

With huge commodities price increases of the past few years, and hurricane Katrina with the resulting severe run up in our area on the cost of technical personnel, one might ask how this could be done. Savings came from a number of areas:

1. We moved from replacing all the existing panels with one standard stainless steel design new panel to retrofitting most existing panels (which were typically in outdoor near-indestructible stainless steel or indoor in near-new condition Nema 12 enclosures)with new interior subpanels and RTU/radio replacements.

2. The RTU manufacturer selected offered a suitable HMI display as part of their package at no additional cost, so the additional touchscreen that was specified and not really wanted or needed by the City and was eliminated.

3. Instead of attempting to provide one design that fit all cases, we came up with 4 basic layouts all using the same basic hardware. One of the additional benefits of this approach is that the RTU's could once again be consolidated with their pump panels, simplifying wiring and thus maintenance troubleshooting. This is contrasted with the previous RTU installation had typically been tacked on in a separate box, requiring allot of wire splicing, complicating wire tracing and troubleshooting.

4. We also proposed a few custom layouts for the individual sites that really needed new enclosures. To those few sites we added considerably to the scope as most everything electrical needed renewal.

5. In two cases, there was an existing local PLC that could serve as the RTU, so that no separate RTU was required.

6. We were able to add in full re-documenting of the all stations electrically. As the specs stood, there was only a requirement to document the newly added equipment, which would still leave the City's maintenance personnel without adequate documentation for troubleshooting each station.

6. Where this solution really saved, though, was in cutting the installation costs to a fraction of what it originally had been (the original figure was shared with me by the electrical subcontractor at near $500K)

So we eliminated allot of waste in unnecessary enclosures, HMIs and installation costs which would have provided no real benefit to the project.

An alternative is to rebid in 2008 the Phase II contract as originally proposed. Based upon the past 2004 low bid of $1.3M, the requested escalation in 2006 of $375K and additional escalation to 2008, the bid price can reasonably be expected to be in the neighborhood of $2M.

Given the importance of getting this project completed, we had conferred with City maintainance and agreed we would both work toward getting this proposal complete and to the director before we did the installation on Pump Station 3. More on that next blog entry....

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