Ukraine tracks the quality and quantity of Russian weapons used against them. This is part of an 0ngoing effort to track Russian dependence on foreign components, usually electronic, for many of their weapons systems. Particularly troublesome are dual-use items that are used in military and non-military equipment. Sometimes Russia finds a way to adapt a civilian item to military use. That item, and its adaptation, is added to the sanctions list. Russia is constantly seeking ways to get around the sanctions, such as using the electronics in major household appliances in military UAVs. The only way to track their success at that is to constantly shift through the debris left behind when a guided weapon strikes and catalog the key components. Sanctions are easy to declare but requite a lot of effort to make them work.
Ukraine has been sanctioning Russian military gear since 2014. That was because there were many Ukrainian-made guidance systems used in Russian air-to-air missiles. This includes the infrared (heat seeking) guidance systems for short-range R-73 and medium-range R-27T. These missiles are the main armament for MiG-29, Su-27, Su-30 and Su-35 fighters.
Su-27/30 aircraft contain a lot of Ukrainian components (hydraulic systems, electrical and electronic systems) as well as braking parachutes. Those components are also produced in Russia but not enough of them to meet the current needs. This dependence on Ukrainian components has an impact on Russian warplane exports. Some of the existing export deals will be seriously jeopardized without Ukrainian components. When the Russians lose access to Ukrainian production their only choice is to delay deliveries to the Russian air force in order to service the signed export contracts.
After 2014 Russia quickly felt the effects of being cut off from their Ukrainian defense suppliers. Although they seized over a dozen factories in Crimea, including three large shipyards, that was still not enough for their needs. Without cooperation from Ukrainian suppliers, Russian military modernization and export plans were in big trouble. The situation was so desperate that the Russians considered buying needed components from China, which has long been manufacturing illegal (unauthorized) copies of these items for the illegal copies of Russian aircraft and missiles they also build.
One of the most important Ukrainian aviation suppliers is Motor Sich, which produces many of the new engines (and modernizes old ones) for the Mi-8/17 transport helicopters and Ka-50/52, Mi-28 and Mi-24/35 attack helicopters. Despite considerable effort, Russian industry has been not able to produce sufficient helicopter engines for planned aircraft production. Without Ukrainian engines Russia, will be unable to produce the required number of new helicopters for both their own forces and export orders. They will also be unable to refurbish enough older engines to keep existing helicopters operational.
Another area where Russians have troubles is military shipbuilding. Russia simply lacks construction facilities so their shipbuilders alone cannot carry out the ambitious plans for replacing all the aging Cold War era ships with new designs. Meanwhile, Ukraine has three shipyards in Mykolayiv along with more yards in Kherson, Kerch and Sevastopol. The last two have already been seized by Russia, something Ukraine is very angry about.
In Mykolayiv, there is also Zorya-Mashproekt, the largest firm designing and manufacturing gas turbine engines for Russian existing and planned warships. Their engines are used on a majority of the ships of the Russian Navy’s ships. Russia has failed to organize domestic production of such gas turbines so the reliability of its fleet is threatened.
A lot of Russian combat vehicles are using Ukrainian components for fire control, laser warning and other complex electronic and optical systems. Even if the Russian industry has alternative sources, getting them up to speed will take time.
After 2022 it was discovered that France and Germany had supplied many of the components Ukraine no longer exported to Russia. France and Germany explained that they believed these items were dual-use but their governments did not have a system for detecting deception. Attention was paid to similar Iranian efforts to buy dual-use items and European firms will accept enforcement if their government presents the evidence. The new post-2022 list will work if all NATO nations cooperate. The Ukrainian list is a key part of that and the reason why Ukraine devotes so much effort to it.