A comprehensive QA-QC framework

1 Copyright 2012 Omega Geo-Consulting Pty Ltd PO Box 7646 - Cloisters Square - WA 6850 - Australia - +61 8 9367 8770 - - February 2012 OMEGA Geo-Consulting Pty Ltd A comprehensive QA-QC framework A project was conducted to design a QA-QC framework that enables the close monitoring of data quality throughout all the stages of a drilling campaign. The view was taken that a drilling campaign can be broken down into 6 linked processes P1 to P6. A process delivers an output that becomes the input into the next process (Figure 1). MethodsPersonnelEquipmentMaterialsTask DiagramProcess MapInputsStartOutputsEndyesnoActivityAct ivity MapStartnoyesEndTaskOutputsInputs yes / no decision pointFigure 26 linked ProcessesDrill the holesPrepare drill campaignP1P2 Validate dataP5 Store in databaseP6 Dispatch labCollect labP4P3 Log coreSample coreBag samples Label bags Figure 1 Core DrillingActivity Design of the QA-QC framework The six processes were mapped (Figure 2) following a detailed review of the practices in place.

2 Quality assurance (QA) standards were then developed and included the definition of measurable critical-to-quality (CTQ) characteristics closely connected to the geologist s quality goals. Operation of the QA-QC framework A check sheet is used to collect the quality control (QC) data (see Table 1). Each process has a specific check sheet targeting inputs, outputs and control factors (methods / personnel / equipment / materials) relevant to the process CTQ s. The field technician records their observations into the check sheet by means of an easy-to-use 1 - 2 - 3 scoring system closely related to the QA standards (see Table 2).

3 A rating on the scale of 1-to-10 is computed based on the actual scores. The rating serves to show how the process performs relative to agreed thresholds and to make the best possible decision regarding the process output(s). On the example of P2: accept the hole as drilled or get it re-drilled. CTQ-Group 1 CTQ-G1 CTQ-Group 2 CTQ-G2 Quality TableEvaluation CTQ-G1 (weight 3)Evaluation CTQ-G2 (weight 5)Accept (1) / Reject (0)Evaluating CTQ-Groups Computing the rating Making a decisionCTQ 1 CTQ 2 CTQ Output 1 Input 1 (CTQ)Process control factor 1 (CTQ)Input 2 (CTQ) CTQ scoresOutput 2 Capturing CTQ scores8106chronological sequence of drill-holesRating [0, 10]AcceptMonitorReject32 Standards are honouredDefects are toleratedDefects are not accepted1 Defects cannot be corrected ANDdata quality is severely compromisedDefects can be corrected ORhave a low impact on data qualityNo defectsQuality specifications are met Table 2 Table 1 Figure 3 Imaginary data only !

4 Control charts assist in detecting any suspicious variations or trends in process performance, which is an added benefit of the methodology Figure 3 plots the P2 rating as the campaign progresses.