Alpay Teoman YILDIZ - 030050014 - 3rd week

Affinity Diagram:

An Affinity Diagram is a tool that gathers large amounts of language data (ideas, opinions, issues) and organizes them into groupings based on their natural relationships.  The Affinity process is often used to group ideas generated by Brainstorming.

Basic Tools for Process Improvement, Module 4, p.2

Kano Diagram:

The Kano diagram is a well proven concept. It is a model of what prompts customers to select one product or service over another.

The Kano Diagram, Rewhorn, M. p.4

Construction Costs:

Some of the factors underlying construction cost trends are straightforward -such as sharp increases in materials cost- while others are complex, and sometimes less transparent in their impact. Moreover, the recent rise in many  utility construction cost components follows roughly a decade of relatively stable (or even declining) real  construction costs, adding to the “sticker shock” that utilities experience when obtaining cost estimates or  bids and that state public utility commissions experience during the process of reviewing applications for  approvals to proceed with construction.

Rising Utility Construction Costs, Chupka M.W., Basheda G., p.1

Preventive Maintenance Costs: 

1- Computers & Instrumentation

2- Software

3- Staff

Justifying Predictive Maintenance, Nichol R., p.4

Emre Ayaroglu - Unanswered terms ( 2nd week)

Cost Reduction

Cost reduction requires a study using relative costs as an important parameter. The unit cost of a product can vary widely. Unless highly automated, assembly operations for such products can become a significant portion of the overall cost.Cost reductions can be achieved by a thorough analysis of all the cost incurred in each phase in the manufacture of a product. Some opportunities for cost reduction are following:

- Simplifying part design and the number of subassemblies required.
- Specifying broader dimentional tolerances and allowing rougher surface finish.
- Using less expensive materials
- Investigating alternative methods of manufacturing
- Using more efficient machines and equipment(Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, 5th Edition, pg. 1265)

Random Sampling

Taking a sample from population or lot in which each item has an equal chance of being included in the sample. Thus, when taking samples from a large bin, the inspector should not take only those that happen to be within reach (Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, 5th Edition, pg. 1121).

Emre Ayaroglu - 3rd week

1- Affinity diagram
2 -Kano diagram
3- Construction cost
4- Operator personnel cost
5- Preventive Maintanence cost
6- Assembly planning
7- Primitive instancing (Type of solid modelling)
8- Spatial Occupancy Enumeration (Type of solid modelling)
9- Direct shell production casting (Rapid prototyping method)
10- Integrated Product Development

Hüseyin DEMİRTAŞ__ 2nd Week UNANSWERED TERMS

Order Management Process


This process includes all the activities between the order acceptance and the customer payment. The major goals are to reduce the process lead time and cost, and to increase the customer satisfaction. Several business functions are involved in performing activities related to the order management process . Information technology can enhance the activity and resource coordination and facilitate communications. Among the different applications that can support the process, multimedia, electronic marketplace, and market analysis and forecasting at a microlevel are the most promising.
(Vito ALBINO, O. Geoffrey OKOGBAA, COMPUTER-AIDED DESIGN, ENGINEERING, AND MANUFACTURING Systems Techniques And Applications, p 11)


Production Process


This process is related to all the activities that transform raw materials in finished products. It has strong interdependencies with engineering, logistics, and order process. Company performances in terms of cost, time, and quality are affected by the coordination level in all manufacturing activities. The major issue is how to create a flow of products without defects and synchronized with the customer request. Manufacturing system layout (for instance, cellular manufacturing), process technology, planning and control techniques, and computer-aided manufacturing applications can enhance performance. However, in several cases (Schonberger 1982 and Womack et al. 1990) the most important benefits have been achieved by modifying work organization through simplification and waste elimination. Also, teams have shown to be highly effective to increase worker commitment and reactive response to problems (Cutcher-Gershenfeld et al. 1994). These characteristics are essential to improve flexibility and productivity.
(Vito ALBINO, O. Geoffrey OKOGBAA, COMPUTER-AIDED DESIGN, ENGINEERING, AND MANUFACTURING Systems Techniques And Applications, p 11)





Global Manufacturing Planning and Control


The last two decades have been characterized by the growing globalization of economic and social scenarios. In particular, multinational corporations (MNCs), due to their global market, have been experimenting a tight competition taking the advantage of their contemporary presence in different countries (Porter 1990). Companies could better achieve the exploitation of these advantages by the coordination of a network of geographically dispersed subsidiaries. The coordination may concern some as well as all the value chain activities, such as research and development, product and process design, engineering, marketing, supply, manufacturing, distribution, and so on. Global manufacturing planning and control refers to the problem of coordinating a MNC’s manufacturing activities. Since such manufacturing activities involve the entire network made up of the MNC’s subsidiaries, coordination should extend to the global supply network and distribution channels and it must also deal with the attendant logistics issues. Specific problems and techniques related to the synchronization of production rate with demand rate in global manufacturing are reviewed by Pontrandolfo and Okogbaa (1997).
(Vito ALBINO, O. Geoffrey OKOGBAA, COMPUTER-AIDED DESIGN, ENGINEERING, AND MANUFACTURING Systems Techniques And Applications, p 38)

Gani Can Öz - 2nd Week Unanswered Terms

Euro Emission Standarts

The European Union is introducing stricter limits on pollutant emissions from light road vehicles, particularly for emissions of nitrogen particulates and oxides. The Regulation also includes measures concerning access to information on vehicles and their components and the possibility of introducing tax incentives.

In order to limit pollution caused by road vehicles, this Regulation introduces common requirements for emissions from motor vehicles and their specific replacement parts (Euro 5 and Euro 6 standards). It also lays down measures improving access to information on vehicle repairs and promoting the rapid production of vehicles in compliance with the provisions of the Regulation.

Regulation (EC) No 715/2007 of the European Parliament

Onur OZAYDIN_2nd_Week_UNANSWERED_TERMS

@FLEXIBLE ASSEMBLY SYSTEM (FAS)
ADDITION : FOR EXAMPLE, THE GENERAL MOTORS PLANT FOR THE SATURN SUBCOMPACT AUTOMOBILE IS DESIGNED WITH (FAS). THIS SYSTEM IS CAPABLE OF ASSEMBLING UP TO A DOZEN DIFFERENT TRANSMISSION AND ENGINE COMBINATIONS AND POWER STEERING AND AIR CONDITIONING UNITS.

(MANUFACTURING ENGINEERING AND TECHNOLOGY, 5^TH EDITION, S. KALPAKJIAN, S.R. SCHMID, p/1182)

@VISUAL SENSING
ADDITION : IN LINEAR ARRAY, ONLY ONE DIMENSION IS SENSED, SUCH AS THE PRESENCE OF AN OBJECT OR SOME FEATURE ON ITS SURFACE.

MATRIX ARRAYS SENSE TWO OR EVEN THREE DIMENSIONS AND ARE CAPABLE OF DETECTING, FOR EXAMPLE, A PROPERLY INSERTED COMPONENT IN A PRINTED CIRCUIT OR A PROPERLY MADE SOLDER JOINT (ASSEMBLY VERIFICATION)

(MANUFACTURING ENGINEERING AND TECHNOLOGY, 5^TH EDITION, S. KALPAKJIAN, S.R. SCHMID, p/1174)

503101307 Onur ÖZAYDIN

A. Selim PARLAKYİĞİT - 2nd Week Missed Term

Layering Technology:

Almost all RP Systems use layering technology in the creation of prototype parts. The basic principle is the availability of the computer software to slice a CAD model into layers and reproduceit in a "output" device like a laser scanning system. The layer thickness is controlled by a precision elevation mechanism. It will correspond directly to the slice thickness of the computer model and the cured thickness of resin. The limiting aspect of the RP system tends to be the curing thickness rather than the resolution of the elevation mechanism.

(Chua C., Leong K.F. and LIM C.S. Rapid Prototyping: Principles and Applications Page: 47-48)

İbrahim İLGÜZ 030040113 (Third Week)

Integrated Product Development (IPD)
Very few products are developed by an individual working alone. It is unlikely that an individual will have all the necessary skills in marketing, industrial design, mechanical and electronic engineering, manufacturing processes and materials, tool-making, packaging design, graphic art, and project anagement, etc. Development is normally done by a design team as an integrated approach. The team leader draws on talent in a variety of disciplines, often from both outside and inside of the organization. As a general rule, the cost of a development effort is a factor of the number of people involved and the time required fostering the initial concept into a fully refined product.Integrated product development (IPD) practices are recognized as critical to the development of competitive products in today's fast-paced global economy. Product development teams, particularly when team members are collocated, are a critical element of IPD practices to facilitate early involvement and parallel design of products and their processes. As a company grows larger and products become more complex, hierarchical organizations are established to master the increasingly large organization size, the technical complexity, and the specialization that evolves to master this complexity. This company growth also results in the geographic dispersion of people and functional departments. These factors inhibit many of the informal relationships that previously provided effective communication and coordination between functions. Functional departments tend to focus inwardly on functional objectives. This is often described as the functional bin. A hierarchical organization structure with enterprise activities directed by functional managers becomes incapable of coordinating the many cross-functional activities required to support product development as the enterprise moves toward parallel design of product and process and a focus on time-to-market. Product development teams (PDTs) are a way to address this complexity by organizing the necessary skills and resources on a team basis to support product and process development in a highly interactive, parallel collaborative manner.
(Computer-Based Design and Manufacturing An Information-Based Approach, Emad Abouel Nasr,. Ali K. Kamrani;p 305)
Operator Personnel Cost (Co)
This cost covers all costs associated with the operation and maintenance support of the system throughout its product life cycle subsequent to equipment delivery in the field. Specific categories cover the cost of system operation, maintenance, sustaining logistic support, equipment modifications, and system/equipment phaseout and disposal. Costs are generally determined for each year throughout life cycle. The operations and maintenance is
Co=(Coo+Com+Con+Cop)
where
Coo - cost of system/equipment life cycle operations
Com = cost of system/equipment life cycle maintenance
Con = cost of system/equipment modifications
Cop = cost of system/equipment phase-out and disposal
(Computer-Based Design and Manufacturing An Information-Based Approach, Emad Abouel Nasr,. Ali K. Kamrani ,p 39)
PRODUCT DATA EXCHANGE SPECIFICATION (PDES)
A likely alternative to IGES is the product data exchange specification (PDES) developed
by IGES organisation. PDES is aimed at defining a more conceptual model. Parts will be
based on solids and defined in terms of features such as holes, flanges, or ribs. Instead of
dimensions PDES will define a tolerance envelope for the parts to be manufactured. PDES
will also contain non-geometric information such as materials used, manufacturing process
and suppliers. PDES will be a complete computer model of the part.
( CAD/CAM/CIM, P. Radhakrishnan S. Subramanian V. Raju,p590)
Spatial Occupancy Enumeration:
The object is represented by a list of the cubical disjoint spatial cells that it occupies. This is the special case of the cell decomposition where the shape of the cells is cubical.
(Computer-Based Design and Manufacturing An Information-Based Approach, Emad Abouel Nasr,. Ali K. Kamrani, p 85 )

M. Burak Toprakoğlu - 030070082 - 3rd week

Life expectancy of products: The life of expectancies of product can vary significantly, depending on the materials and processes employed (hence the quality) and on many other factors - especially the frequency and quality of maintenance required. Numerous examples can be given where a choice has to be made between different processes and materials to manufacture a product. For example, consider the following: (a) sheet metal versus cast-iron frying pans, (b) carbon-steel versus stainless-steel exhaust systems for automobiles, (c) wood versus metal handles for hammers, (d) plastic versus metal outdoor furniture, and (e) aluminum versus reinforced-plastic ladders.

(Kalpakjian S. Schmid S.R.,Manufacturing Engineering and Technology, 5th Edition, p. 1244)

Tool-post grinders: Tool-post grinders are self-contained units and usually are attached to the tool post of a lathe. The workpiece is mounted on the headstock and is ground by moving the tool post. These grinders are versatile, but the lathe components should be protected from abrasive debris.

(Kalpakjian S. , Schmid S.R. ,Manufacturing Engineering and Technology, 5th Edition, p. 816)

Demand forecasting: Risk and uncertainty is deeply associated with every business decision. An essential element of any business decision is to fore see the future and act accordingly. A look at the future without factual analysis renders a business devision more of a gambling than real growth oriented decision. Amongst all forecasts of business. Demand forecast is the key driver for success or failure. Future demand of the product acts as a game changing factor in today’s competitive business environment. Demand forecasting is essential to guard the future against any surprises. For example, if a manager fails to forecast high demand in the future, the mobilisation of resources to meet that demand will become a cumbersome task and might result in a lost opportunity to increase market share.

(S. A. Siddiqui, A. S. Siddiqui, Managerial Economics And Financial Analysis, 1th Edition, p.80)

Make or Buy: Fundamentally, make or buy is about the choice of whether to carry out a particular process or activity within your own business or to buy it in from a supplier. In reality, this can take many forms: choice about making a particular small part of a complex larger products (for example, if we make turbine generators, should we make the ball bearings that go into them?), choices about system and subsystem manufacture (if we make cars, should we make the engine?), choices about which particular manufacturing processes to have in the company (if our manufacturing process requires a specialised heat treatment, should we beuy the plan tor use a specialises subcontractor?). Although the examples given are from manufacturing businesses, the same issues apply to other in or outscoring decisions.

The distinctive feature of manufacturing industry is the variety of processes involved and hence the frequency with which the issue is encountered, with the resulting greater scope for good or bad decisions to affect the business result.

(D. Probert, Developing a Make or Buy strategy for manufacturing business, p. 1,2)

Buğra Cengiz 030060178 3.week Term 4

 

• Multiple process controlstations located throuhout the plant to control of the indivual loops and devices of the process

• A central control room equipped with operator stations, where supervisory control of the plant is accomplished.

Groover, Automation, Production Systems and CIM. P.102

With the development of the microprocessor, it became feasible to connect multiple microcomputers together to share and distribute the process control workload, The term distributed control system (DCS) is uded to describe such a configuration. which consists of the following components and features:

• Local operator stations ditributed throughout the plant. This provides the DCS with redundancy. If a control failure occurs in the central control room. the local operator stations take over the central control functions. If a local operator station fails, the

other local operator stations assume the functions of the failed station.

• All process and operator stations interact with each other by means of a communications

network, or a data highway as it is often called

Gökhan Güngör (3rd week)

1- Make or Buy
2- Life Expectancy
3- Use Value
4- Esteem Value (Prestige Value)
5- Recycling
6- Green Engineering
7- Resolution
8- Rule of 10
9- Hundred Percent Inspection
10- Acceptance Sampling

Didem Tarkun(503101304) - 2nd week - definitions

1. Closed loop lifecycle management
For fundamentally reducing environmental burden dueto artifacts and their production processes, it isessentially important to realize a pre-designed closedproduct life cycle, and to manage it for less productsand energy flow without excessive overhead load.This concept has been well implemented for large scaleindustrial products and facilities, but not for massproducedconsumers' durable goods. For improvingthis situation, we have proposed a methodology fordesign and management of a closed product life cycle,based on the following idea: promoting the informationsharing among manufacturers and users, motivatingusers to participate in design and managementactivities, incorporating product take-back processesinto product basic functionality, and innovating aconcept and structure of products and their life cycle.A method consists of four steps: design of productlife cycle by tight adaptation to product usage modes ofmass customers, creation of new life cycle scenariowhere users can play an active role for closing the lifecycle, creation of new product concept and structurewhich is adapted to the proposed life cycle scenario, designing efficient methods for managing productionand maintenance/recycling facilities for new productsand production systems. Many technical issues forthose steps are still under discussion. Somepreliminary explanation and case studies are given inthis paper for further elaboration of the method.

F Kimura - Proc. 33th CIRP Int. Seminar on Manufacturing, 2000 - ptech.pcd.go.th

2. Sustaining engineering
Sustaining engineering often can be more challenging than developing a new piece of code. It requires a complete and comprehensive understanding of the existing architecture, design goals, key technologies, and functionality as it was originally envisioned. It demands a disciplined approach to provide a workable solution under a tremendous time pressure while introducing zero regression.
Phases:
Ramp up: Short ramp up with fundamentals, foundational skill set, environment, formal technology training, process training, knowledge acquisition through deep dive, explorative testing, and ad-hoc testing
Productive: Able to perform simple tasks, continuous self-paced training, and occasional formal training. Work products by the individual contributors are reviewed internally (buddy review, group review) and externally by our customer’s engineering team
Efficient: Able to solve and carry out more complex issues, and occasionally requires help from other experienced engineers. Focus on improving deeper understanding of finer details of product issues
Optimal: Equivalent level of proficiency as the existing experienced engineers. Improving or fine tuning process
Reaching the steady state is achieved by rigorous training, feeding and caring of the team members, providing technical guidance and oversight, and proactive performance management.

Augmentum, Product development outsourcing, sustaining engineering, 2010

3. Product and portfolio management
Effective portfolio management is vital to successful product innovation. Portfolio management is about making strategic choices—which markets, products, and technologies our business will invest in. It is about resource allocation—how you will spend your scarce engineering, R&D, and marketing resources. It focuses on project selection—on which new product or development projects you choose from the many opportunities you face. And it deals with balance—having the right balance between numbers of projects you do and the resources or capabilities you have available.
Portfolio management for product innovation – picking the right set of development projects – is critical to new product success. This article reports on the new product portfolio practices and performance of a large sample of firms in North America. Reasons why portfolio management is important are identified, followed by the relative popularity of the different portfolio techniques: financial methods are first, followed by business strategy methods, bubble diagrams and scoring models. Next, how the various portfolio methods fare in terms of six performance metrics is probed. Financial methods, although the most popular and rigorous, yield the worst results overall, while top performing firms rely more on non-financial approaches – strategic and scoring methods. The details of how some of these more popular methods are employed by firms to rate and rank development projects are also provided. Finally, managerial implications, including suggestions for making portfolio management more effective in industry, are outlined.

New Product Portfolio Management: Practices and Performance
Robert G. Cooper, Scott J. Edgett, Elko J. Kleinschmidt, 12 AUG 2004, DOI: 10.1111/1540-5885.1640333

Portfolio management for new product development: results of an industry practices study
Robert Cooper, Scott Edgett, Elko Kleinschmidt, 17 DEC 2002, DOI: 10.1111/1467-9310.00225

4. Depreciation time
The tool planning problem is to determine how many tools should be allocated to each tool group to meet some objectives. Recent studies aim to solve the problem for the cases of uncertain demand. Yet, most of them do not involve cycle time constraints. Cycle time, a key performance index in particular in semiconductor foundry, should not be ignored. The uncertain demand is modeled as a collection of scenarios. Each scenario, with an occurrence probability, represents the aggregate demand volume under a given product mix ratio. A genetic algorithm embedded with a queuing analysis is developed to solve the problem. Experiments indicate that the proposed solution outperforms that obtained by considering only a particular scenario.

The cost of tools that a mechanic uses in the normal operations of the business can be depreciated. Depreciation expense is deducted over the course of the tools' useful life. The number of years to use in calculating your depreciation will vary depending on the type of tools; a large tool such as a floor jack has a longer useful life than a small hand tool such as a wrench. Consult Internal Revenue Publication 946 for help in determining the number of years to use in calculating the depreciation.

How to Depreciate a Mechanic's Work Tools, Johanna Miller, December 1, 2010
A tool planning approach considering cycle time constraints and demand uncertainty, Muh-Cherng Wu, Yai Hsiung and Hsi-Mei Hsu, DOI 10.1007/s-0003-2030-2

Ertan Toparlak-2nd Week Unanswered Terms

1-Computer aided production management (CAPM):CAPM is the use of the computers to improve the efficiency and effectiveness of production management.It is concerned what the manufacture ,in which order and by when.CAPM concerned with the executing of customers orders,efficiently and economically.Purpose of the CAPM is use of computer-based information to support production management functions and to coordinate flows of orders ,materials and finished goods.

(AN INTRODUCTION TO COMPUTER AIDED PRODUCTION MANAGEMENT-1st Edition-Stephen J. Childe-P.34)

2-Master Production Schedule (MPS):Master production schedule contains the requirements for finished goods and dates for their completion.In most companies this is usually a mixture of firm orders and sales forecasts.

(AN INTRODUCTION TO COMPUTER AIDED PRODUCTION MANAGEMENT-1st Edition-Stephen J. Childe-P.39)

Ertan TOPARLAK-503091329

Ozan Kovancı - 3rd Week

1. SPT (Shortest Processing Time)

2. Push System

3. Demand Forecasting

4. Muda

5. Mura

6. Muri

7. Jikoda

8. Yoidon

9. Job Sequence

10. Geometric Transformations

Ezgi UĞUR - 030060195 3rd Week

Computer-Aided Sorfware Engineering (CASE)

Computer-aided sorfware engineering (CASE) encompasses computer-based procedures, techniques, and tools which can be used to develop, maintain, and reengineer software. CASE is to the sorfware engineer as computer-aided design/computer aided manufacturing (CAD/CAM) (4. v.) is to the mechanical engineer and computer-aided electrical engineering (CAEE) is to the electrical engineer. Although the variety of technological alternatives can be bewildering, the concepts of CASE provide a commonsense approach to engineering quality software more productively.

The application of CASE is intended to allow teams of software engineers to produce softwarethat:

* meets business and system requirements

* is completed within a predictable Schedule

* is available within budget guidelines

* allows for easy maintenance and enhancement

(David Sharon, Computer Aided Software Engineering, p. 278)

Parameter Data Section (PD)

An IGES file consist of five sections which must appear in the following order: start section, global section, directory entry (DE) section, parameter data (PD) section, and terminate section.

The PD section contains the actual data defining each entity listed in the DE section. For example, a straight line entity is defined by the six coordinates of its two endpoints. While each entity is always two records in the DE section, the number of records required for each entity in the PD section varies from one entity to another (the minimum is one record) and depends on the amount of data. Parameter data are placed in free format in columns 1 through 64. The parameter delimiter (usually a comma) is used to separate the list of parameters. Both delimiters are specified in the global section of the IGES file. Column 65 is left blank. Columns 66 through 72 on all PD records contain the entity pointer specified in the first record of the entity in the DE section.

(Emad Abouel Nasr, Ali K. Kamrani, Computer-Based Design and Manufacturing, pp. 127-129)

Shortest Processing Time (SPT)

In single-machine scheduling problem, sequencing the jobs in increasing order of processing time is known as shortest processing time (SPT) sequencing. In single-machine scheduling, sometimes we may be interested in minimizing the time spent by jobs in the system. This in turn will minimize in process inventory. Also, we may be interested in rapid turnaround/throughput times of the jobs. The time spent by job in the system is nothing but its flow time and the “rapid turnaround time” is the mean flow time of the jobs in the system. Shortest processing time (SPT) rule minimizes the mean flow time.

(R. Panneerselvam, Operations Research, Second Edition, p. 496)

Jikoda

Jikoda is the ability to stop production due to a problem. Production may be stopped automatically by a machine or by on operator (Levinson, 2002). The idea here is that a quality issues should be fixed right away, at the source of the problem. Traditional manufacturing systems, which emphasize production over quality, allow the defect to work its way down the system. This allows the defect to "grow" and end up being a more expensive tix. At the same time because the defect is caught so far down stream, often the root cause is not identified and corrected. Jikoda utilizes the machine operator to identify quality concerns and correct them right away. It is critical that the operator has the authority and responsibility to stop the process and fix the error.

(Christian Gausman, Implementing Lean Manufacturing and Design for Manufacturing Concepts in a Job Shop Manufacturing Environment, pp. 17-18)

Özgür Cebeci ,030060158 ,3rd Week

Spot drilling : When drilling holes , a small chamfer – or even small corner break – is very desrible at the top of the hole . A chamfer will eliminate burrs or sharp edges that are the natural result of drilling , allowing a smoother entry of a tap , or just eliminating the burrs for easier handling . Spot drill is a tool that is used fort his purpose ; it resembels a regular drill and has two main pruposes:

· To start-up a hole with a small dmple at its exact location

· To machine a chamfer on a hole , contolling the depth ıf cut.

(CNC programming techniques , Peter Smid ; pg. 8 , First edition)

Maximum material condition : MMc is that condition of a par tor feature which contains the maximum amounth of materail ,e.g. minimum size hole , or a maximum size shaft. In certain cases its use allows an increase in the specified tolerances if it is indicated that the tolerance applied to the feature at its maximum material condition.

The maximum material principle take into account the mutual dependence of tolerances of size , form orientation and/or location and permits additional tolerance as the cosidered feature departs form its maximum material condition.

(Manual of engineering drawing , Colin H. Simmons,Dennis E. Maguire,Neil Phelps ; pg. 183 , first edition)

International Tolerance Grade (IT): A group of tolerances that vary depndending on the basic size , but that provide the same relative levels of accuracy within a given grade. An “international Tolerance grade “ establishes the magnitude of the tolerance zone or the amoungh of part size variation allowed for external and internal dimentions alike. Tolerances are expressed in grade number that are consistent with ınternational tolerance grades identified by the prefix IT , such as IT6 , IT11, etc. A smaller grade number provides a smaller tolerance zone.

( Shop reference for students and apprentices , Edward G. Hoffman,Christopher J. McCauley ; pg . 223. 2nd edition)

Uniform annunal cost method: The uniform annunal cost method involves axpressing all expenditures in terms of uniform annual costs. Some analysts prefer this method for pavement because routine maintenance exprenditures can be conveniently expressed as uniform annual costs without the need for a discounting process . however , one –time expenditures such as rehabilitation cost must be first converted to a present value , then to an annunal cost.

(Portland cement concrete resurfacing ; Kenneth H. McGhee , pg 36 . )

Doğuş Cendek-030060101- 3rd Week

Rate-of-return method

The rate of return method also called return-on-investment (ROI) method,goes slightly beyond the present worth (PW) and uniform annual cost (UAC) methods by actually calculating the rate of return that is provided by the investment.If the calculater rate is greater than the criterion rate of return,the investment is acceptable.
To determine the return on investment,an equation must be set up with the rate of return as the unknown.Either the PW method or the UAC method can be used to establish the equation.Then the value of the interest rate i that drives the aggregate PW of UAC to zero is determined.

(Groover M.,Automotion,Production Systems and CIM Practice Hall 1st edition,p. 50)

Present worth method

The present worth method uses the equivalent present value of all current and future cash flows to evaluate the investment proporsal.The future cash are converted into their present worth by using the appropriate interest factors.Accordingly,some ,nterest rate must be used in the factors.This interest rate is decided in advance and represents the rate-of-return criterion that the company is using to evaulate its investment opportunities.If the aggregate present worth of the project is positive,the return from the project exceeds the rate-of-return criterion.If the present worth of the project is negative,the project does not meet the rate-of-return criterion.

(Groover M.,Automotion,Production Systems and CIM Practice Hall 1st edition,p. 49)

Boring Cycle (G85 Code)

The boring operation requires that the tool move at a programmed feedrate when it is between points R and Z.The format of the statement for calling the boring cycle subroutine is G85XxYyZzRrFfLl

(Chang C.H., Melkonof M.A.,NC Machine Programming and Software Design Practice Hall,p.48)

Facing Cycle (G94 Code)

Facing is an operation used to reduce the length of a turned part as opposed to turning operation whose function is reduce its diameter.

(Chang C.H., Melkonof M.A.,NC Machine Programming and Software Design Practice Hall,p.51)

Olcay Türkoğlu (3rd week)

1. Maximum Material Condition (MMC)

2. International Tolerance Grade (IT)

3. Fit (for dimensioning and tolerancing)

4. Payback Period Method

5. Present Worth Method

6. Uniform Annual Cost Method

7. Rate-of-Retun Method

8. Boring Cycle (in G-coding)

9. Spot Drilling (in G-coding)

10. Facing Cycle (in G-coding)

503101505

Evrim Berk 030060161 3rd Week

Depth Of Cut: The depth of cut is determined by the width of the chip. During the roughing operation, the depth of cut is usually much more greater than that of the finishing operation.. For turning, it is one-half the difference between the inner and the outer diameters of the workpiece.

(Computer Aided Manufacturing, Chang T., Wysk R.A., Wang H., 2nd edition, 1998, Page: 141)

Geometric Transformations: In order to manipulate a modeling object in the space, geometric transformations are used. There are two kinds of geometric transformation, that of transforming the object and transforming the coordinate system. First one moves the object within the existing coordinate frame, such as moving the primitives in solid modelling. Second one moves the coordinate system, and then the object is viewed from the new coordinate frame such as finding a better view or doing a 2-D orthogonal projection. The transformation methods are the same for both cases, except the signs are changed.

(Computer Aided Manufacturing, Chang T., Wysk R.A., Wang H., 2nd edition, 1998, Page: 106)

Resolution: Resolution is also called sensivity. It is the smallest increment of motion of the machine components.

(Manufacturing Engineering and Technology, Kalpakjian S., Schmid S.R., 5th edition, Page: 1159)

Push System: In traditional manufacturing, the parts are made in batches, placed in inventory, and used whenever necessary. This approach is known as a push system, meaning that parts are made according to a schedule and are placed in inventory to be used whenever they are needed.

(Manufacturing Engineering and Technology, Kalpakjian S., Schmid S.R., 5th edition, Page: 1226)

Burak Çınar 030060132 3rd week

Phosphate coatings:

Phosphate coatings are formed by immersing metals (usually steel or zinc) in baths where metal phosphates (iron, zinc, and manganese phosphates are all common) have been dissolved in solutions of phosphoric acid. The resultant coatings can be used to precondition surfaces to receive and retain paint or enhance the subsequent bonding with rubber or plastic. In addition, phosphate coatings are usually rough and can provide an excellent surface for holding oils and lubricants. This feature can be used in manufacturing, where the coating holds the lubricants that assist in forming, or in the finished product, as with black-color bolts and fasteners, whose corrosion resistance is provided by a phosphate layer impregnated with wax or oil.

(MATERIALS AND PROCESSES IN MANUFACTURING 10th edition, J. Temple Black, Ernest Paul DeGarmo, Ronald A. Kohser, p.953)

Payback Period Method:

The payback period method represents an extension of the cost and accounting rate of return methods. This method determines the period of time that it takes for the original capital investment to be returned completely in the form of revenues, thus making it possible to roughly evaluate the risk of various investment objects. An individual investment object is favorable if its playback period is shorter than the investor's target specification. when comparing alternatives, the alternative that has the shortest playback period is the one that should be selected.

(Factory Planning Manual, Michael Schenk, Siegfried Wirth, Egon Müller, p.302)

Muda:

Muda is a japanese word referring to work or to elements of production that do not add value to the product. Therefore, it is important to eliminate muda. The job attitude of looking for muda and finding ways to eliminate it is called kaizen. Kaizen is central to the TPS (Toyota production system) way of thinking. In TPS, muda has been classified into a number of categories such as correction (rework), overproduction, processing, conveyance, inventory, motion and waiting.

(Handbook of design, manufacturing, and automation, Richard C. Dorf,Andrew Kusiak, p.568)

Mura:

Mura literally means unevenness, which may be due to irregular production volumes or changing work flows or production schedules. It means that the workloads on the machines are not balanced. In such a situation, capacity planning must be done that considers the peak level of production, thereby increasing the cost of production.

(Handbook of design, manufacturing, and automation, Richard C. Dorf,Andrew Kusiak, p.568)