
Data Lab for Social Good, Cardiff University in collaboration with HISP Centre, University of Oslo
2025/10/29

Outline

The Problem: A tale of two data streams
Health supply chains are struggling with forecasting at sub-national/ facility level.
Operational realities: Incomplete records, irregular orders, frequent manual adjustments.
This masks true demand and leads to a cycle of…
Persistent, critical stockouts 📉.
But… we have a success story.
Platforms like DHIS2 and CHAP have robust, high-performing models for forecasting disease cases (morbidity).
✅ We’re good at forecasting cases (e.g., malaria).
❌ We’re struggling with forecasting consumption (e.g., antimalarials).
Can we leverage the CHAP/DHIS2 morbidity models to forecast product consumption in supply chains?
Case data and consumption data are different.
Different Data Structures
Consumption data is “messier”.
Different Metadata
Consumption is affected by logistics.

Our research questions
To solve this, we are investigating three key questions:
Portability: When can we transfer a model? (Morbidity \(\rightarrow\) Consumption? One product \(\rightarrow\) Another?)
Decision Translation: How do we turn a statistical forecast into a better inventory order? (Forecast \(\rightarrow\) Action)
Hierarchical Coherence: Do site-level forecasts reliably add up for district and national planning?

We’ve organized our work into three interconnected Work Packages (WPs).
WP1: Portability (Test reuse/transfer. Create “if/then” rules.)
\(\downarrow\)
WP2: Forecast \(\rightarrow\) Inventory (Translate forecasts into real-world inventory policy.)
\(\downarrow\)
WP3: Hierarchical Coherence (Test aggregation for national procurement.)
Our immediate focus is on WP1 (Portability) and linking to WP2 (Inventory Simulation).
We used number of dengue cases in Laos to test the forecasting models.
Figure 1: Monthly dengue cases by location.
Best values in each column are highlighted in bold.
| Model | MASE | Quantile Loss (q10) | Quantile Loss (q50) | Quantile Loss (q90) |
|---|---|---|---|---|
| Random Forest | 0.864 | 107.360 | 383.058 | 607.857 |
| ARIMA Madagaskar | 0.902 | 165.565 | 360.123 | 310.765 |
| Auto ARIMA Reg | 0.913 | 173.929 | 367.735 | 322.289 |
| Auto ARIMA | 0.950 | 176.069 | 376.163 | 309.962 |
| Linear Regression | 1.008 | 129.647 | 416.129 | 278.839 |
| LightGBM | 1.009 | 96.771 | 452.020 | 752.016 |
| Linear Regression Reg | 1.035 | 127.927 | 391.573 | 284.118 |
| Auto EWARS | 1.041 | 125.371 | 421.408 | 296.665 |
| xgBoost | 1.057 | 103.980 | 485.837 | 817.878 |
| INLA baseline | 1.082 | 126.139 | 432.163 | 239.886 |
| Mean | 1.090 | 138.155 | 461.150 | 347.705 |
| ETS | 1.099 | 124.722 | 428.761 | 299.443 |
| sNaive | 1.217 | 138.155 | 510.311 | 276.443 |
| Naïve | 1.221 | 143.645 | 506.282 | 319.259 |
Figure 2: Overall MASE accross forecast origins
Figure 3: Overall MASE accross forecast origins for each location.

Way forward
Leverage CHAP/DHIS2 based models for supply chain data.
Evaluate forecast perfromance based on time series structure, region and across products.
Run order up-to-level based inventory simulations.
Evaluate how forecast performance translate into inventory decisions.

Key takeaways
The Idea: Reusing morbidity models for supply chains is a promising but non-trivial opportunity.
Our Contribution: We’re building an evidence-based, practical guide for when and how to repurpose morbidity models for consumption forecasting, leveraging CHAP’s modelling infrastructure and DHIS2-linked data.
The Impact: By aligning forecasts with operational decisions, this work aims to improve stock availability, and inform sourcing/procurement decisions.
Compatibility: CHAP/DHIS2’s external model interface makes it possible to integrate these forecasting tools seamlessly, no new platform required.