Makina osindikizira achikhalidwe omwe amasindikizira makina osindikizira omwe amapezeka kale chifukwa cha zovuta zake. Njira zosindikiza wamba zosindikiza zimangodalira kwambiri pa - zopangidwanso ndi zomwe zimathandizira kuti zisokonekere. U
Otsatsa omwe ali ndi chiphunzitso cha "mtundu woyamba, khulupirirani woyamba ndi woyang'anira wokalambayo" kuti awonetsetse kuti malonda abwino ndi okhazikika.