From 649935a6c9156a35e551f592a7a3bf9f39d7fd4e Mon Sep 17 00:00:00 2001
From: Alex Dewar <a.dewar@imperial.ac.uk>
Date: Wed, 22 Apr 2026 14:32:24 +0100
Subject: [PATCH 1/4] Fix incorrect lifetime in warning message about old
 assets

Fixes #1220.
---
 src/asset/pool.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/asset/pool.rs b/src/asset/pool.rs
index 899dcb84a..3b0007fd9 100644
--- a/src/asset/pool.rs
+++ b/src/asset/pool.rs
@@ -35,11 +35,11 @@ impl AssetPool {
             // Ignore assets that have already been decommissioned
             if asset.max_decommission_year() <= year {
                 warn!(
-                    "Asset '{}' with commission year {} and lifetime {} was decommissioned before \
+                    "User asset '{}' with commission year {} was decommissioned in {}, before \
                     the start of the simulation",
                     asset.process_id(),
                     asset.commission_year,
-                    asset.process_parameter.lifetime
+                    asset.max_decommission_year
                 );
                 continue;
             }

From e26e6869e3c33d1d05e9baab39eee684a2b6e017 Mon Sep 17 00:00:00 2001
From: Alex Dewar <a.dewar@imperial.ac.uk>
Date: Wed, 22 Apr 2026 16:15:40 +0100
Subject: [PATCH 2/4] Add placeholder sections to release notes doc

---
 docs/release_notes/upcoming.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/docs/release_notes/upcoming.md b/docs/release_notes/upcoming.md
index b20948d96..dc4fc050a 100644
--- a/docs/release_notes/upcoming.md
+++ b/docs/release_notes/upcoming.md
@@ -13,3 +13,15 @@ ready to be released, carry out the following steps:
   version
 
 -->
+
+## New features
+
+<!-- TODO -->
+
+## Breaking changes
+
+<!-- TODO -->
+
+## Bug fixes
+
+<!-- TODO -->

From 2eccf45066bcc7185c93967c35692b07a0f341e4 Mon Sep 17 00:00:00 2001
From: Alex Dewar <a.dewar@imperial.ac.uk>
Date: Wed, 22 Apr 2026 16:17:11 +0100
Subject: [PATCH 3/4] Add this bugfix to release notes

---
 docs/release_notes/upcoming.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/docs/release_notes/upcoming.md b/docs/release_notes/upcoming.md
index dc4fc050a..438946a27 100644
--- a/docs/release_notes/upcoming.md
+++ b/docs/release_notes/upcoming.md
@@ -24,4 +24,6 @@ ready to be released, carry out the following steps:
 
 ## Bug fixes
 
-<!-- TODO -->
+- Fix misleading warning message for assets decommissioned before simulation start ([#1259])
+
+[#1259]: https://github.com/EnergySystemsModellingLab/MUSE2/pull/1259

From 9d58c1129c0973545a3de65f13b216a45b5e3696 Mon Sep 17 00:00:00 2001
From: Alex Dewar <a.dewar@imperial.ac.uk>
Date: Thu, 23 Apr 2026 15:00:06 +0100
Subject: [PATCH 4/4] Disallow assets where `max_decommission_year ==
 commission_year`

---
 src/asset.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/asset.rs b/src/asset.rs
index a56ea7d7f..be92a0c24 100644
--- a/src/asset.rs
+++ b/src/asset.rs
@@ -340,8 +340,8 @@ impl Asset {
         let max_decommission_year =
             max_decommission_year.unwrap_or(commission_year + process_parameter.lifetime);
         ensure!(
-            max_decommission_year >= commission_year,
-            "Max decommission year must be after/same as commission year"
+            max_decommission_year > commission_year,
+            "Max decommission year must be greater than commission year"
         );
 
         Ok(Self {