Question 1

Your products show strong seasonality (Tet peak +300%) and are affected by unplanned promotions from modern trade channels. How would you build a demand forecasting model to achieve MAPE below 15%?

Accepted Answer

Combine 3 forecast layers: (1) Statistical baseline model - time series with seasonality adjustment; (2) Market adjustment layer - integrate promotion data from MT and sales feedback; (3) Collaborative forecasting - S&OP alignment between Sales, Marketing, and Supply Chain. Technical points to cover: time series analysis (Holt-Winters for seasonality, ARIMA for trend); importance of clean historical data (removing outliers from stockouts and extreme promotions); demand sensing from supermarket POS data (Big C, Co.opmart, Winmart); promotion uplift modeling; distinguishing MAPE applicability for fast-moving SKUs vs. slow-moving SKUs (where MAE or bias is more appropriate); managing Sales override mechanisms to avoid political bias.

Question 2

Your key raw material supplier - accounting for 40% of COGS - has just announced a 15% price increase due to rising global raw material costs. How would you manage this negotiation and build a long-term supplier relationship strategy to minimize dependency risk?

Accepted Answer

Run 2 parallel tracks: (1) Short-term negotiation (0-3 months) - analyze supplier's actual costs, find leverage; (2) Long-term strategy (3-18 months) - diversify supply base, develop backup suppliers. Negotiation track: request open-book costing (supplier cost breakdown analysis); verify actual raw material price movements through commodity indices; propose a price escalation clause (formula-based price adjustment); offer long-term volume commitment in exchange for price stability. Strategy track: classify suppliers using Kraljic matrix (critical/leverage/routine/bottleneck); develop at least 2 qualified suppliers for each critical material; local sourcing to reduce FX risk and logistics exposure; supplier development program for Vietnamese suppliers.

Question 3

Your company has a history of conflict between Sales and Supply Chain - Sales commits high volumes to hit targets but Supply Chain cannot produce in time, resulting in simultaneous stockouts and excess inventory. How would you design and implement an S&OP process to resolve this conflict?

Accepted Answer

Design S&OP in 5 monthly steps: (1) Data review (days 1-5): consolidate actuals vs. plan; (2) Demand review (days 6-10): Sales/Marketing update forecast; (3) Supply review (days 11-15): Supply Chain assesses fulfillment capability; (4) Pre-S&OP (days 16-20): resolve gaps at management level; (5) Executive S&OP (days 21-25): CEO/CFO approve final plan. Critical change management points: S&OP fails not from lack of process but from lack of senior leadership commitment; CEO must chair the Executive S&OP; Sales must have accountability for forecast errors (tied to KPIs); need a single 'one number' - all departments use the same forecast figure; measure forecast accuracy using OU% (Over-commitment Utilization); the danger of 'hockey stick patterns' in Sales forecasts; the role of a neutral S&OP champion/facilitator.

Question 4

Your company has Days of Inventory Outstanding (DIO) of 85 days, versus an industry benchmark of 45 days. The CFO demands reduction to 50 days within 12 months without reducing service level. How would you approach this inventory optimization challenge?

Accepted Answer

12-month roadmap across 3 parallel lanes: (1) Quick wins (months 1-3): liquidate/reduce slow-moving and obsolete stock; (2) Process improvement (months 3-9): improve demand forecast, reduce supplier lead time, optimize safety stock; (3) Structural change (months 6-12): review network design, vendor-managed inventory, postponement strategy. Root cause analysis for high DIO: classify inventory by ABC + aging buckets (0-30, 31-60, 61-90, 90+ days); excess and obsolete inventory often accounts for 20-30% of DIO in Vietnamese companies; EOQ and safety stock calculation to determine optimal levels; postponement strategy (delay personalization to the final stage); hedging inventory for price-volatile materials; distinguishing 'cycle stock' from 'safety stock' from 'pipeline inventory' in the analysis.

Question 5

At the start of 2020, factories in China suddenly closed, completely disrupting your component supply. What did you do or what would you do to respond in the short term and build long-term supply chain resilience?

Accepted Answer

Respond across 3 time horizons: (1) Short-term (0-4 weeks): triage the situation, activate emergency sourcing, prioritize existing inventory; (2) Medium-term (1-6 months): urgently diversify geographic supply base; (3) Long-term (6-24 months): redesign supply chain for built-in resilience. Short-term: form a 24/7 crisis team, audit actual inventory across all locations (not just at the factory), immediately contact all secondary (tier-2) suppliers, prioritize production by margin and customer commitments. Long-term - lessons from Vietnam's 2020-2022 reality: China+1 strategy (partial shift to Southeast Asia - Thailand, Malaysia, Indonesia); build buffer stock for critical components; supplier mapping to tier-3; nearshoring for some components. Top candidates mention Business Continuity Plan (BCP) and Supply Chain Risk Assessment.

Question 6

A major EU customer requires you to provide an ESG (environmental, social, governance) report for your supply chain, including the carbon footprint of all transport and labor conditions at tier-1 and tier-2 suppliers. This is the first time your company has received such a request. Where do you start and how do you build the roadmap?

Accepted Answer

4-phase roadmap: (1) Baseline assessment (months 1-2): inventory existing data and identify gaps; (2) Data collection and measurement (months 2-6): scope 1/2/3 carbon footprint, supplier audits; (3) First-time reporting (month 6): GHG Protocol framework; (4) Improvement and emission reduction targets (month 7+). Knowledge points to demonstrate: distinguishing Scope 1 (direct emissions from company vehicles, machinery), Scope 2 (electricity consumption), Scope 3 (entire supply chain - most complex); CBAM (Carbon Border Adjustment Mechanism) of the EU - impacts exports to EU from 2026; SA8000 and SMETA (Sedex) standards for labor conditions; the reality that many Vietnamese suppliers lack ESG data (company must help them); cost of compliance and the opportunity to turn ESG into a competitive advantage; green logistics options (electric vehicles, green warehouse).