Production Planning and Inventory Control Sesi 1: Pengantar Theory of Constraints MM Eks Mud – 1 Juli 2009 Alain Widjanarka

Sejarah Perkembangan 1979 : OPT (OPTIMIZED PRODUCTION TIMETABLES)  SOFTWARE UTK FINITE SCHEDULING 1982 : OPT (OPTIMIZED PRODUCTION TECHNOLOGY)  SOFTWARE 1984 : SYNCHRONOUS MANUFACTURING (Oleh General Motor) 1987 : TOC (THEORY OF CONSTRAINT) DIPELOPORI OLEH Dr. ELIYAHU M. GOLDRATT, SEORANG AHLI FISIKA DARI ISRAEL

Eliyahu Goldratt Eli Goldratt is an educator, author, scientist, philosopher, and business leader. But he is, first and foremost, a thinker who provokes others to think. Often characterized as unconventional, stimulating, and "a slayer of sacred cows," Dr. Goldratt exhorts his audience to examine and reassess their business practices with a fresh, new vision. List of books by Eli Goldratt : The Goal It’s Not Luck (lanjutan The Goal) Critical Chain (TOC dalam Project Mngmt) The Race (Drum Buffer Rope) What is this thing called TOC ? The Haystack Syndrome Necessary but not sufficient (teknologi) ……. BSc from Tel Aviv University MSc & PhD from Bar – llan University Founder of Avraham Y Goldratt Institute

Theory Of Constraints (TOC)  TOC juga dikenal dengan nama-nama lain seperti Constraints Management (CM), Synchronous Flow Manufacturing (SFM), Synchronous Production, dan OPT.

TOC SUATU FILSAFAT MANAJEMEN YANG MEMANDANG SUMBERDAYA DAN AKTIFITAS SUATU ORGANISASI SEBAGAI UNSUR-UNSUR DARI JEJARING YANG SALING BERGANTUNG DAN MEMANAJEMENINYA SEDEMIKIAN RUPA AGAR BISA MENGOPTIMALKAN KINERJA KESELURUHAN ORGANISASI UNTUK SAAT INI DAN MASA DEPAN

 An organizations is a complex web of people, equipment, methods, materials and measures. Add to this detail complexity the dynamic complexity of the changes introduced by customers, suppliers, workforce, and regulations, among other elements, and you have a picture of the challenges faced by today’s management team.  Traditionally, management has divided the organization into smaller, more manageable pieces with the objective to maximize the performance of each part. After all, global improvement is the sum of local improvements. Right? TOC’S PARADIGM

 Wrong! TOC holds that changes to most of the variables in an organization usually have only small impacts on global performance – that is, on the bottom line. There are few variables -- perhaps only one -- for which a significant change in local performance will effect a significant change in global performance.  Such a variable is called a constraint. Therefore, if you wish to achieve more of your goal, you must identify your constraint, focus on it, and follow through. That is the essence of TOC! TOC’S PARADIGM

 It is based on the fact that, like a chain with its weakest link, in any complex system at any point in time, there is most often only one aspect of that system that is limiting its ability to achieve more of its goal.  For that system to attain any significant improvement, that constraint must be identified and the whole system must be managed with it in mind. TOC’S PARADIGM

A Chain Is Only As Strong As… Its Weakest Link

 It is based on the simple fact that multi-phase processes, in whatever setting, can only move at the pace of the slowest step.  The way to speed up the process is to use a catalyst to work on the slowest step and make it work at capacity to speed up the whole process. TOC’S PARADIGM

 The theory emphasises being clear about finding and supporting the main limiting factor. In describing the theory these limiting factors are called 'constraints'.  Constraints could be an individual, a team, a piece of equipment or a local policy, or the absence of some tool or piece of equipment. TOC’S PARADIGM

 Seluruh resources dan aktifitas organisasi adalah elemen dari jaringan yang interdependent,  Perlu dikelola untuk mengoptimalkan kinerja organisasi secara keseluruhan (bukan parsial)  Kinerja sistem dibatasi oleh constraints  Optimalisasi kinerja sistem dicapai melalui optimalisasi pemanfaatan constraint TOC’S PARADIGM

untuk sebuah sistem, global optima ≠ jumlah local optima

SYSTEM SYSTEM ADALAH ENTITAS YANG KEBERADAAN SERTA FUNGSINYA DITENTUKAN OLEH INTERAKSI DARI KOMPONEN-KOMPONENNYA.

SYSTEM KUMPULAN/TUMPUKAN KOMPONEN-KOMPONEN YANG SALING TERKAIT YANG TIDAK LAGI BERFUNGSI SENDIRI-SENDIRI SEKEDAR KUMPULAN KOMPONEN FUNGSINYA BERUBAH BILA SALAH SATU KOMPONEN DIAMBIL ATAU DITAMBAH. BILA SYSTEM DIBELAH, FUNGSINYA AKAN RUSAK. FUNGSINYA TIDAK BERUBAH BILA KOMPONENNYA DITAMBAH ATAU DIKURANGI. BILA TUMPUKAN DIBELAH, AKAN DIEROLEH DUA TUMPUKAN SUSUNAN KOMPONEN SANGAT MENENTUKAN SUSUNAN KOMPONEN TIDAK RELEVAN KOMPONEN-KOMPONEN SALING TERIKAT DAN BERFUNGSI BERSAMA KOMPONEN-KOMPONEN TIDAK SALING TERIKAT DAN BERFUNGSI SENDIRI-SENDIRI PERILAKUNYA DITENTUKAN OLEH STRUKTUR KESELURUHAN PERILAKUNYA DITENTUKAN OLEH JUMLAH KOMPONEN PERBANDINGAN SISTEM DENGAN KUMPULAN

LIMA LANGKAH PENINGKATAN PROSES (FIVE FOCUSING STEPS) 1.CARI KENDALA SISTEM 2.TENTUKAN CARA UNTUK MEMAKSIMUMKAN PEMANFAATAN KENDALA SISTEM 3.USAHAKAN HAL-HAL LAIN MENUNJANG KEPUTUSAN INI 4.TINGKATKAN KENDALA SISTEM 5.BILA PADA LANGKAH SEBELUMNYA KENDALA TELAH TERATASI, KEMBALI KE LANGKAH PERTAMA. JANGAN BIARKAN INERTIA MENJADI KENDALA

ALIRAN ‘SYNCHRON’ ALIRAN TIDAK SYNCHRON TOC DALAM MANAJEMEN PRODUKSI

JENIS-JENIS KENDALA (CONSTRAINTS) KENDALA KAPASITAS KENDALA MATERIAL KENDALA PASAR KENDALA MANAJERIAL KENDALA LOGISTIK SHORT TERM & LONG TERM BOTTLENECK & CCR TYPE, QUANTITY LIMIT, PRICE, LEAD TIME, QUALITY STANDARD STRATEGIES & POLICIES PLANNING & CONTROL SYSTEM

Throughput ($) Operating Expense ($) Inventory ($) Aliran uang dalam perusahaan

PERBANDINGAN UNSUR-UNSUR PERSAINGAN NON SYNCHRONIZED OR HIGH-INVENTORY OPERATION SYNCHRONIZED OR LEAN PRODUCTION OPERATION SERVICE RESPONSIVENESS DELIVERY RELIABILITY

UNSUR-UNSUR PERSAINGAN NON SYNCHRONIZED OR HIGH-INVENTORY OPERATION SYNCHRONIZED OR LEAN PRODUCTION OPERATION PRICE QUALITY PERBANDINGAN (lanjutan)