（1）工(gong)程機械(xie)使(shi)用(yong)(yong)初期(qi)(qi)(qi)階段的(de)(de)故(gu)(gu)(gu)障(zhang)特點。工(gong)程機械(xie)在使(shi)用(yong)(yong)初期(qi)(qi)(qi)(相(xiang)當(dang)于走(zou)合(he)期(qi)(qi)(qi))其故(gu)(gu)(gu)障(zhang)是(shi)由高(gao)到(dao)低(降曲線)，使(shi)用(yong)(yong)初期(qi)(qi)(qi)故(gu)(gu)(gu)障(zhang)率高(gao)低是(shi)隨制(zhi)造或(huo)(huo)維修(xiu)質(zhi)量(liang)和走(zou)合(he)時(shi)期(qi)(qi)(qi)的(de)(de)使(shi)用(yong)(yong)有(you)關．如(ru)果工(gong)程機械(xie)制(zhi)造或(huo)(huo)修(xiu)理(li)質(zhi)量(liang)高(gao)，并(bing)能正(zheng)確地(di)(di)使(shi)用(yong)(yong)與維護。那么，初期(qi)(qi)(qi)故(gu)(gu)(gu)障(zhang)率就低。否則早(zao)期(qi)(qi)(qi)故(gu)(gu)(gu)障(zhang)率會高(gao)。早(zao)期(qi)(qi)(qi)故(gu)(gu)(gu)障(zhang)多地(di)(di)是(shi)聯接(jie)螺栓(shuan)(shuan)松動(dong)或(huo)(huo)松脫；管道接(jie)頭松動(dong)或(huo)(huo)松脫：殘(can)留金(jin)屬屑或(huo)(huo)鑄造砂易堵(du)塞油道或(huo)(huo)夾在相(xiang)對運動(dong)摩擦中拉傷機件(如(ru)液(ye)壓系統中的(de)(de)執行機構油缸)造成漏油，調(diao)整(zheng)后的(de)(de)間隙(xi)或(huo)(huo)壓力發生(sheng)變(bian)化，使(shi)機件不能執行規定能力，有(you)些接(jie)合(he)因(yin)螺栓(shuan)(shuan)不緊而漏水、漏油、漏氣(qi)等。

（2）工(gong)程機(ji)械正(zheng)常使用階(jie)段(duan)的故(gu)(gu)障特點。工(gong)程機(ji)械走合期(qi)結(jie)束后，進(jin)人正(zheng)常使用階(jie)段(duan)。工(gong)程機(ji)械在(zai)這(zhe)個階(jie)段(duan)內運行，只要按規(gui)定(ding)維護和正(zheng)確使用，一(yi)般不會發生故(gu)(gu)障，即便發生故(gu)(gu)障，也(ye)是隨機(ji)性的故(gu)(gu)障。