During the last decade the ZU-23 anti-aircraft artillery gun was improved by Precocious Machine building Design Bureau. Russian improved ZU-22M variant has increased performance and maintenance characteristics. A number of other countries make the ZU-23 improvement work on their own. Finnish company Instrumentointi Oy and VAMMAS Oy jointly install a semi-automatic target tracking system, laser rangefinder, ballistic computer, engine for turning barrels in both planes, and a number of other improvements.
In Poland the ZU-23 is rebuilt to a missile-artillery system by adding two "Strela-2M2" (2K32M) shoulder launched anti-aircraft guided missiles and new optical sight with a target pointing system. This improved modification was indexed as ZUR-23-2S "JOD". With the absence of radio electronic strays the target should be defeated by the guided missiles while if the target use radio electronic countermeasures or it is not rational to use guided missiles the target should be defeated by the anti-aircraft gun. Furthermore fighting against ground forces an improved variant of the ZU-23 shows the same efectivity.
The Russian improved ZU-23M lost it's ZAP-23 sight and the operator working place and were replaced to electro mechanic turn systems, sighting control panel, binocular collimator sight with built in miniature video device and glowing glass for air and ground targets. New optical electronic system includes a laser rangefinder, television channel, optical mechanic device can be reinforced with thermo location channel and a television system for usage at night. Also automatic target lock and tracking device, ballistic computer, indication and control panel, external target pointing system (datalink).
All mentioned equipment is placed on a rotating carriage mount right side from the anti-aircraft guns. Furthermore there is ability to place two "Igla" (9K38), "Stinger" or some other shoulder launched anti-aircraft guided missiles.
The main improvement objective was to increase fire efectivity to low flying targets including the low silhouette ones with a hit probability from 0.023 to 0.3 - 0.4 depending from the target speed. The ZU-23M also defeats targets at day/night time.