diff --git a/src/importer/index.ts b/src/importer/index.ts
index a2bf4be..44d265c 100644
--- a/src/importer/index.ts
+++ b/src/importer/index.ts
@@ -1,6 +1,7 @@
 import { Config, ImportOptions, Thing } from "@types";
 import { adapters } from "../adapters";
 import { DummyOpenHAB, OpenHAB } from "../openhab";
+import { partitionBy } from "../utils/list";
 
 
 const createFilter = (filter?: string) => {
@@ -11,13 +12,8 @@ const createFilter = (filter?: string) => {
   return new Function("$", `const v = ${filter}; if(typeof v !== 'boolean') throw new Error("Filter should be of boolean type"); return v;`) as ((_: Thing) => true);
 };
 
-export const importThings = async (config: Config, options: ImportOptions) => {  
-  const OH = options.dryRun ? DummyOpenHAB : OpenHAB;
-  const openhab = new OH(config.openHAB);
-
-  const sources = options.sources ?? Object.keys(config.sources);
-
-  const things = (await Promise.all(sources.map(source => {
+const discoverThingsFromSources = async (sources: string[], config: Config, options: ImportOptions): Promise<Thing[]> => {  
+  const promises = sources.map(source => {
     const { type, config: cfg } = config.sources[source];
     
     const constructor = adapters[type as keyof (typeof adapters)];
@@ -27,22 +23,30 @@ export const importThings = async (config: Config, options: ImportOptions) => {
     }
 
     return new constructor(source, cfg).loadThings();
-  }))).flat();
+  });
 
-  const existingThings = await openhab.getThings();
-  const existingThingsUIDs = existingThings.map(t => t.UID);  
-
-  const filter = createFilter(options.where);
-  
-  const thingsToImport = things
-    .filter(t => !existingThingsUIDs.includes(t.UID))
-    .filter(filter);
-
-  if (options.force) {
-    await openhab.deleteThings(...thingsToImport.map(t => t.UID));
-  }
-
-  await openhab.createThings(...thingsToImport);
-
-  return thingsToImport;
+  const responses = await Promise.all(promises);  
+  return responses.flat().filter(createFilter(options.where));
+}
+
+export const importThings = async (config: Config, options: ImportOptions) => {  
+  const OH = options.dryRun ? DummyOpenHAB : OpenHAB;
+  const openhab = new OH(config.openHAB);  
+
+  const sources = options.sources ?? Object.keys(config.sources);
+  const allThingsToImport = await discoverThingsFromSources(sources, config, options);
+
+  const allThingsInOH = await openhab.getThings();
+  const existingThingsUIDs = allThingsInOH.map(t => t.UID);    
+
+  const [existing, missing] = partitionBy(allThingsToImport, t => existingThingsUIDs.includes(t.UID));
+  
+  if (options.force) {
+    await openhab.deleteThings(...existing.map(t => t.UID));
+    await openhab.createThings(...allThingsToImport);
+    return allThingsToImport;
+  }
+  
+  await openhab.createThings(...missing);
+  return missing;
 }
diff --git a/src/utils/list.ts b/src/utils/list.ts
new file mode 100644
index 0000000..0ca3419
--- /dev/null
+++ b/src/utils/list.ts
@@ -0,0 +1,3 @@
+export const partitionBy = <T>(list: T[], condition: (item: T) => boolean): [T[], T[]] => {
+  return [list.filter(e => condition(e)), list.filter(e => !condition(e))];
+}
\ No newline at end of file