Production Systems Control

In a manufacturing plant, inventories consist of basic materials, good in process, and finished stock. Production planning is concerned with determining what resources (materials,supplies,space,people,and equipment) must be available on-site over time to ensure that manufacturing goals are accomplished. Production control is concerned with timely issuance of available on-site materials to the manufacturing process in such a way that materials are made available in a cost-effective manner where and when needed. The fundamental purpose of inventory is to provide an essential decoupling between unequal flow rates.EOQ and EPQ were early mathematical formulations that considered some of the important costs associated with inventory, but less mathematically rudicable aspects, such as immediacy of quality feedback effects, were not represented in these early formulations. The use of Just In Time (JIT) in recent times has demonstrated that these earlier formulations were therefore significantly incomplete and misleading.
Most manufacturing firms learned to incorporate MRP (Material Requirements planning)systems to keep track of lead times and assembly builds. With the introduction of JIT systems, so much less inventory is work-in-process and is on the production floor for such a short time that, as a component of overall inventories, work-in-process inventory has typically been greatly reduced or even no longer exists as a material category.
The development of the kanban system by Toyota and the concentration of effort on the reduction of setup time by such innovative thinkers as Shigeo Shingo have greatly enhanced the banafits of adopting a JIT philosophy. Reducing the setup time is now seen as productivity opportunity, whereas in the past it was typically ignored-something we wanted to do but never got around to doing.
Quality control and quality assurance promised but often failed to deliver in indentifying quality problem at source. It was never a production responsibility, and so, as a staff function, it rarely got the resources it needed or the attention it deserved for doing the job right. Making quality a production responsibility has focused increased attention on quality needs, and making the production team take responsibility for identifying and resolving quality issues has greatly enhanced the team's effectiveness. The quality control department, a technical staff resource, can now be effectively employed as the technical means of assisting production productivity and of helping quality teams employ the technology needed to resolve problems.
Taguchi techniques, a technical area that for years in the United States has been called design-of-experiments, is a fairly technically demanding area that needs to be applied to production problems by those with sufficient statistical training. A partnership is needed between those in production who have the problems and those skilled in statistical analysis to effectively capitalize on these opportunities.

Source: Industrial Engineering and Management book's

Frederick W. Taylor

Member of the American of the American Society of Mechanical Engineers (ASME), much impressed by the concepts offered by Towne (Henry Towne of the Yale and Towne Company published a paper Transactions f the American Society of Mechanical Engineers, stressed the need for engineers o be concerned with the econoimic effects of their decisions), was Frederick W. Taylor. Taylor have ofetn been referred to as the "father of industrial Engineering". Taylor offered the concept that it was an engineering responsibility to design, measure, plan, and schedule work.
Taylor, influenced by both Towne and Wentworth, developed the concept that work design, work measurement, production scheduling, and other staff functions were engineering responsibilities. His attempts to implement his concepts revolutionized industrial productivity.
Even more important than the improvement in shoveling productivity was the concept of applying engineering analysis to human work situations. Taylor initiated the practice of performing an engineering analysis of work requirements specifying the exact method, tools, and equipment to be employed, and then training the worker to perform the opearations as specified.
He eventually determined an optimum method of selected workers to perform this task and carefully trained them to perform the task, exactly as he specified. As a result of his analysis, dramatic changes in pig iron handling productivity resulted.
Analysis of the work requirements and specifications for a method to perform an operation is now called work design or methods study. However, Taylor also pioneered the activity we now generally call work measurement. This activity is concerned with determining the amount of time an operator should be allowed for performing an operation.
Taylor invented stopwatch timestudy, which is still used extensively to determine the time to perform an operation, commonly referred to today as a time standard. Taylor development of timestudy led to time standards, which are the underlying basis for control of labor costs and are a necessary input to scheduling and pricing activities in industry.
Industrial Engineering, which represents the science of operations, has not been embraced by many responsible for operations today; they choose to deny its existence a century after its initiation. they choose to believe that operation simply require common sense. the history of engineering is replete with such attitudes. There are firms just today discovering that industrial engineering effectively deals with problems they have been unable to solve effectively throughout their past. In a sense, even today, in some firms, doing industrial engineering work ia a bit like doing missionary work.

WIMAX

WiMAX, (Worldwide Interoperability for Microwave Access) adalah merupakan teknologi akses nirkabel pita lebar (broadband wireless access atau disingkat BWA) yang memiliki kecepatan akses yang tinggi dengan jangkauan yang luas.Disamping kecepatan data yang tinggi mampu diberikan, WiMAX juga merupakan teknologi dengan open standar. Dalam arti komunikasi perangkat WiMAX diantara beberapa vendor yang berbeda tetap dapat dilakukan (tidak proprietary). Dengan kecepatan data yang besar (sampai 70 MBps), WiMAX dapat diaplikasikan untuk koneksi broadband ‘last mile’, ataupun backhaul.Yang membedakan WiMAX dengan Wi-Fi adalah standar teknis yang bergabung di dalamnya. Jika WiFi menggabungkan standar IEEE 802.11 dengan ETSI (European Telecommunications Standards Intitute) HiperLAN sebagai standar teknis yang cocok untuk keperluan WLAN, sedangkan WiMAX merupakan penggabungan antara standar IEEE 802.16 dengan standar ETSI HiperMANSebagai teknologi yang berbasis pada frekuensi, kesuksesan WiMAX sangat bergantung pada ketersediaan dan kesesuaian spektrum frekuensi.Secara umum terdapat beberapa alternatif frekuensi untuk teknologi WiMAX sesuai dengan peta frekuensi dunia. Dari alternatif tersebut band frekuensi 3,5 GHz menjadi frekuensi mayoritas Fixed WiMAX di beberapa negara, terutama untuk negara-negara di Eropa, Canada, Timur-Tengah, Australia dan sebagian Asia. Sementara frekuensi yang mayoritas digunakan untuk Mobile WiMAX adalah 2,5 GHz.



Isu frekuensi Fixed WiMAX di band 3,3 GHz ternyata hanya muncul di negara-negara Asia. Hal ini terkait dengan penggunaan band 3,5 GHz untuk komunikasi satelit, demikian juga dengan di Indonesia. Band 3,5 GHz di Indonesia digunakan oleh satelit Telkom dan PSN untuk memberikan layanan IDR dan broadcast TV.




Keuntungannya adalah WiMAX salah satu teknologi memudahkan mereka mendapatkan koneksi Internet yang berkualitas dan melakukan aktivitas. Sementara media wireless selama ini sudah terkenal sebagai media yang paling ekonomis dalam mendapatkan koneksi Internet. Area coverage-nya sejauh 50 km maksimal dan kemampuannya menghantarkan data dengan transfer rate yang tinggi dalam jarak jauh, sehingga memberikan kontribusi sangat besar bagi keberadaan wireless MAN dan dapat menutup semua celah broadband yang ada saat ini. Dari segi kondisi saat proses komunikasinya, teknologi WiMAX dapat melayani para subscriber, baik yang berada dalam posisi Line Of Sight (posisi perangkat-perangkat yang ingin berkomunikasi masih berada dalam jarak pandang yang lurus dan bebas dari penghalang apa pun di depannya) dengan BTS maupun yang tidak memungkinkan untuk itu (Non-Line Of Sight). Jadi di mana pun para penggunanya berada, selama masih masuk dalam area coverage sebuah BTS (Base Transceiver Stations), mereka mungkin masih dapat menikmati koneksi yang dihantarkan oleh BTS tersebut. kemudian Sistem kerja MAC-nya (Media Access Control) yang ada pada Data Link Layer adalah connection oriented, sehingga memungkinkan penggunanya melakukan komunikasi berbentuk video dan suara. Siapa yang tidak mau, ber-Internet murah, mudah, dan nyaman dengan kualitas broadband tanpa harus repot-repot. Anda tinggal memasang PCI card yang kompatibel dengan standar WiMAX, atau tinggal membeli PCMCIA (Personal Computer Memory Card International Association) yang telah mendukung komunikasi dengan WiMAX.




Di Indonesia, Wimax memang belum sepopuper Wi-Fi (Wireless Fidelity). Namun sebagai salah satu negara pemegang lisensi Wimax (Worldwide Interoperability Mobile Access), Indonesia memiliki wewenang menerapkan teknologi telekomunikasi ini pada operator-operator seluler yang memiliki kesiapan baik secara kesiapan secara infrastruktur maupun kesiapan operational-maintanance. Akses broadband nirkabel Wimax diharapkan mampu memberikan angin segar di tengah-tengah persaingan industri telekomunikasi dan kebutuhan pasar.

Source :
www.ristinet.com
http://en.wikipedia.org/wiki/WiMAX
http://netsains.com/2008/02/wimax
www.spaink.net/images
http://library.thinkquest.org/04oct/01721/wireless/wimax

Preventive Maintenance

Preventive maintenance is a schedule of planned maintenance actions aimed at the prevention of breakdowns and failures. Preventive maintenance activities include equipment checks, partial or complete overhauls at specified periods, oil changes, lubrication and so on. In addition, workers can record equipment deterioration so they know to replace or repair worn parts before they cause system failure.The ideal preventive maintenance program would prevent all equipment failure before it occurs.Without preventive maintenance, for example, costs for lost production time from unscheduled equipment breakdown will be incurred. Also, preventive maintenance will result in savings due to an increase of effective system service life.Long-term benefits of preventive maintenance include:

Improved system reliability, Decreased cost of replacement,Decreased system downtime,
Better spares inventory management.

Source :http://www.weibull.com/