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CATHODIC PROTECTION FIGURE 1
Work breakdown structure for cost estimation.
activities and demobilization of man- power and equipment.
Sublet Scope This scope includes all work to be sub-
contracted, such as design, installation, materials, delivery, inspections, or com- missioning. It is important to separately categorize these scopes, because the cost estimates involved here are provided by other parties.
Concealed Scope This work includes technical and com-
mercial meetings, arranging for worker QLMV\QÅKI\QWV XI[[M[ \ZIV[XWZ\I\QWV [a[- tems, safety training, safety gear and equipment, medical facilities, external inspections and audits, material packing and tagging, material and equipment loading and unloading, disposal of debris, and housekeeping issues. Figure 1 is an example of a work
breakdown structure for a CP project, showing summarized scopes of work per the preceding categories. The work breakdown structure is a
very powerful tool. It develops a precise scope of work, helps to estimate required resources, and provides baseline data and a framework for project planning, con-
NACE International, Vol. 51, No. 4
trolling, and scheduling at the time of job execution.
Material Cost Estimation The materials, from estimation to
procurement and supply, are a major part of costing. There is very little room for improvising; hence, a smart estimation is ZMY]QZML NZWU Y]ITQÅML IVL M`XMZQMVKML professionals.
Raw Materials Raw materials can be any substances
used in the fabrication and production of finished goods. In CP projects, these materials could be cables, coupons, refer- ence electrodes, rectifier oils, anodes, IVWLM JIKSÅTT[ \PMZUQ\ _MTL UI\MZQIT[ coating repair kits, and raw components of fabricated and designed materials. The cost of these items involves mate-
rial, procurement, and delivery charges. Bulk Materials
This category consists of structural
steel, ready-mix concrete or concrete UI\MZQIT[ JIKSÅTT UI\MZQIT[ XI^MUMV\ restoration materials, mechanical materi- als for brackets and supports, fuel oil, etc. The requirement of these materials can- not be assessed accurately, so costs are
done either by keeping special allowances in estimations or are covered through project overhead expenses. In either case, this should be estimated by well-experi- enced engineers in construction and in- stallation projects.
Fabricated Materials Examples for CP materials include
junction boxes, bonding stations, test sta- tions, anode attachments, and support assemblies. These materials are fabri- cated to suit the custom design. The cost estimates of such items in-
clude the raw/bulk material cost, pro- curement cost, fabrication cost, and de- livery charges.
Engineered/Designed Materials