## 2 Methodology
### Establishing the Context  
In the initial phase of risk analysis (Establishing the Context), the primary objective is to define the overall framework for risk assessment and decision-making in open-pit mine planning. Strategic planning in mining projects operates under complex geological, economic, and operational uncertainties, which must be systematically managed to ensure financial and technical feasibility.  
This study follows the ISO 31000-2018 risk management framework [37], which emphasizes a structured approach to identifying, analyzing, and treating risks associated with mining operations. In this phase, the broader decision-making criteria and risk acceptance thresholds are defined, ensuring that subsequent risk identification and analysis steps are aligned with industry best practices. To establish a structured risk assessment process, the following key elements are defined:  
* Economic indicators as measures of value--most companies have multiple and often conflicting corporate objectives [38; 39], requiring a comprehensive evaluation of financial performance. While net present value (NPV) is widely used as the primary metric for project evaluation and strategic decision-making, additional financial indicators, such as the internal rate of return (IRR) and payback period (PBP), are also considered to address varying investment criteria and risk tolerance. These metrics provide a broader perspective on project feasibility, balancing long-term profitability with short-term financial stability. Net present value (NPV) is calculated according to the following formula: \[NPV=C_{0}+\frac{C_{1}}{\left(1+r\right)^{1}}+\frac{C_{2}}{\left(1+r\right)^{2 }}+\ldots+\frac{C_{t}}{\left(1+r\right)^{t}}\] (1) where \[C_{0}\] --initial cash flow (often negative); \[C_{1}\] --cash flow at time 1;\(C_{2}\)--cash flow at time 2; \(C_{t}\)--cash flow at time t; \(t\)--the time period of the investment; \(r\)--the discount rate.
* Risk acceptance criteria--different levels of risk will be acceptable to different stakeholders (e.g., management, investors, etc.), depending on their risk tolerance and strategic priorities. The level of risk tolerance can vary significantly between organizations, influenced by factors such as corporate policies, financial stability, industry standards, and management preferences. However, in general, a probability of financial loss below 10% is considered favorable for investment and project development. For the purposes of this case study, a probabilistic approach is adopted, where the acceptable risk level is defined such that the probability of obtaining a negative NPV (P(NPV < 0)) must be less than 10%, ensuring that the likelihood of financial failure remains below a critical threshold.
* Data sources and scope--the data for this analysis were collected from multiple sources to ensure a comprehensive assessment of economic and technical uncertainties. Key inputs include geological resource models, historical and empirical data from comparable open-pit mining operations, industry benchmarks, and technical documentation related to mining and processing technologies. Market data, including metal price trends, were sourced from relevant financial and commodity exchanges. Additionally, techno-economic studies and investment reports provided insights into capital and operational cost structures, while regulatory and industry standards guided the selection of economic and risk assessment parameters.  
This phase sets the foundation for Step 2: Risk Identification, where the specific technical and economic parameters influencing mine planning and financial projections are identified.