JIT刚好及时化系统(ppt 41页).ppt

1、1/41,第十六章,剛好及時化系統 Just-In-Time,2/41,章節概要,導論 JIT的目標 建立JIT架構 轉換到JIT系統 服務業的JIT JIT採購 JIT II 作業策略,只有在需要的時候才生產 存貨會明顯減少 一般是小批量生產 是一種精簡生產系統lean production system,3/41,1.導論,剛好及時化系統:重複性的生產系統,其物料與貨品的加工 dealing with breakdowns or problems when they occur Preventive maintenance Proactive approach; reducing brea

2、kdowns through a program of lubrication, adjustment, cleaning, inspection, and replacement of worn parts,34/41,Reasons for keeping equipment running Avoid production disruptions Not add to production costs Maintain high quality Avoid missed delivery dates,Maintenance Reasons,35/41,Production capacit

3、y is reduced Orders are delayed No production Overhead continues Cost per unit increases Quality issues Product may be damaged Safety issues Injury to employees Injury to customers,Breakdown Consequences,36/41,Total Maintenance Cost,Breakdown andrepair cost,Optimum Amount of preventive maintenance,C

4、OST,Total Cost,Preventivemaintenance cost,Table 16S-1,37/41,Preventive maintenance: goal is to reduce the incidence of breakdowns or failures in the plant or equipment to avoid the associated costs Preventive maintenance is periodic Result of planned inspections According to calendar After predeterm

5、ined number of hours,Preventive Maintenance,38/41,Frequency of breakdown / month If the average cost of a breakdown is $1,000, and the cost of preventative maintenance is $1,250 per month, should use preventive maintenance?,Example S-1,39/41,Expected cost to repair = 1.4 breakdowns per month X $1000

6、 = $1400 Preventive maintenance (PM) = $1250 PM results in savings of $150 per month,Example S-1 Solution,40/41,Maintenance interval,Average time before breakdown is normal distribution with mean 3 weeks and standard deviation 0.6 week. If breakdown cost average $1000 and preventive maintenance cost $250 ANS: 250/(250+1000)=0.2 using