We have new releases for Chap:
- chap-core 2.2/2.3 (the backend) and
- Modeling App 7.0 (the frontend/DHIS2 app).
These releases include two major areas of improvement that support operationalization of Chap and the Modeling App by Ministry of Health teams:
- Evaluation: Rigorous, iterative evaluation of model performance is an essential step that should be carried out before using forecasts to inform decisions. These releases make evaluation features more accessible and easier to use, enabling countries to build this step into their workflows, which can help minimize the risk of making decisions based on inaccurate predictions.
- Thresholds: In many forecasting use cases, thresholds are essential for helping determine which predictions should trigger action. These releases make it easier to add and modify thresholds and import them into DHIS2 along with predictions to show in visualizations and generate alerts.
What is new in the Modeling App (7.0)
- Evaluation results at a glance. The evaluation details screen now shows summary metrics, with each metric explained in plain language and suspicious values flagged.
- Evaluation plots for everyone. The plots are no longer behind the “experimental features” switch, show only the forecast horizon you selected, and use clearer labels such as “1 period ahead”.
- Better alert thresholds. When running a prediction you can see and adjust how thresholds are calculated (standard deviations, percentile band, baseline years). The percentile strategy shows a WHO-style endemic channel.
- Import endemic thresholds into DHIS2. Optionally map a data element so threshold values are imported alongside the predictions.
- Easier-to-read charts. Axes and tooltips show month names in your DHIS2 language instead of raw period codes.
- Select org units by group as well as by level (from version 6.3).
- Access tokens. If your chap-core server requires a token, you can set it in the app’s settings and get clear feedback if it is rejected.
- DHIS2 2.40 is no longer supported. The app shows a banner asking you to upgrade.
What is new in chap-core (2.2 and 2.3)
Most of the above is made possible by changes in chap-core. In addition:
- Evaluations keep their settings, so you can see exactly how a result was produced and rerun it later.
- Clearer metrics. Each metric now says whether higher or lower is better, and demonstration metrics have been removed from results.
- Fewer silent failures. Invalid covariate values are rejected upfront with a clear message, and a model that skips org units or periods now fails instead of returning partial results.
- Optional access token for the chap-core API. Existing setups without a token keep working.
- Simpler installation with a single Helm chart and a self-contained Docker Compose file.
There are also many other small improvements and fixes. See the full release notes for details:
- Release v2.2.0 · dhis2-chap/chap-core · GitHub
- Release v2.3.0 · dhis2-chap/chap-core · GitHub
- Release v7.0.0 · dhis2-chap/chap-frontend · GitHub
Upgrading
The chap-core and Modeling app releases go together. The latest Modeling App version (7.0) needs chap-core version 2.3 or newer, and the app tells you clearly if the chap-core version is too old.
Upgrade chap-core to 2.3 first, then install Modeling App 7.0 from the App Hub.
