Create a multiband raster from Landsat 8 band images

Option A:

Use the Composite Bands (Data Management) tool.

1. In ArcMap, navigate to Geoprocessing > ArcToolbox > Data Management Tools > Raster > Raster Processing > Composite Bands.
2. Click the browse button, and search for the desired input raster.


3. Specify the name and location of the output raster, and click OK.

Note:
 If working outside a geodatabase, specify the extension of the output raster. 

Option B:

Use the Composite Bands button in the Image Analysis window.

1. In ArcMap, add the raster bands to the map document.
2. Navigate to Windows > Image Analysis.


3. In the Image Analysis window, hold down the shift key and select the band images.
4. Click the Composite Bands button.

Note:
 The output of the Image Analysis window is added to the map document as a temporary layer. To save the output layer as a raster dataset, click the Export button on the Image Analysis window and specify the output location of the raster dataset. 

Note:
 The output raster of both options is generated as an RGB composite. To change it to a Stretched value composite, right-click the layer > Properties > Symbology. Under the Show section, select the 'Stretched' option, and specify the band to be used for the stretch values. Input the desired parameters, and click OK.