Q1. Explain in brief the origins of Just in Time. Explain the different types of wastes that can be eliminated by JIT?

Ans.

Just in time manufacturing is a process by which companies don’t keep lots of excess inventory; instead they manufacture a product as an order comes in.

The origin of JIT can be traced back to Henry Ford’s production line, in which he was keenly aware of the burdens of inventory. However, Ford’s production system generated large volumes of identical products created in large batches – there was no room for variety, and the system was not coupled to demand levels.

Just-in-Time (JIT) is only one element of lean manufacturing, which is a broader philosophy that seeks to eliminate all kinds of waste in a process.  Although JIT is often considered an enterprise-wide philosophy of continuous improvement, I’d like to focus on the mechanistic aspects of JIT – that is, the development and operations of a production system that employs continuous flow and preventive maintenance. In an effectively implemented JIT production system, there is little or no inventory – which includes Work-In-Process (WIP) – and production is tightly coupled to demand.

Just in Time (JIT) is a management philosophy aimed at eliminating waste and continuously improving quality. Credit for developing JIT as a management strategy goes to Toyota. Toyota JIT manufacturing started in the aftermath of World War II.Although the history of JIT traces back to Henry Ford who applied Just in Time principles to manage inventory in the Ford Automobile Company during the early part of the 20th Century, the origins of the JIT as a management strategy traces to Taiichi Onho of the Toyota Manufacturing Company. He developed Just in Time strategy as a means of competitive advantage during the post World War II period in Japan.The post-World War II Japanese automobile industry faced a crisis of existence, and companies such as Toyota looked to benchmark their thriving American counterparts. The productivity of an American car worker was nine times that of a Japanese car worker at that time, and Taiichi Onho sought ways to reach such levels.

Two pressing challenges however prevented Toyota from adopting the American way:

1. American car manufacturers made lots or a batch of a model or a component before switching over to a new model or component. This system was not suited to the Japanese conditions where a small market required manufacturing in small quantities.

2. The car pricing policy of US manufacturers was to charge a mark-up on the cost price. The low demand in Japan led to price resistance. The need of the hour was thus to reduce manufacturing costs to increase profits.

To overcome these two challenges, Taiichi Onho identified waste as the primary evil. The categories of waste identified included

Overproduction Inventory or waste associated with keeping dead stock Time spent by workers waiting for materials to appear in the

assembly line. Time spend on transportation or movement Workers spending more time than necessary processing an item Waste associated with defective items

Taiichi Onho then sought to eliminate waste through the just-in-time philosophy, where items moved through the production system only as and when needed.

P.T.O

Q2. What is Value Engineering or Value Analysis? Elucidate five companies which have incorporated VE with brief explanation?

Ans:

Value Engineering (VE) or Value Analysis is a methodology by which we try to find substitutes for a product or an operation, VE involves a team of people following a structured process. The process helps team members communicate across boundaries, understand different perspectives, innovate, and analyze.

Value is a personal perspective of your willingness to pay for the performance delivered by a product, process or project.

Good value is achieved when the required performance can be accurately defined and delivered at the lowest life cycle cost.

Value Analysis is an effective tool for cost reduction and the results accomplished are far greater. It improves the effectiveness of work that has been conventionally performed as it questions and probes into the very purpose, design, method of manufacture, etc., of the product with a view to pinpointing unnecessary costs, obvious and hidden which can be eliminated without adversely affecting quality, efficiency, safety and other customer features.

PRINCIPLES OF VE

‘User-First’ AttitudeFunctional ApproachTeam ApproachCreative Approach

VALUE AND VALUE ANALYSIS

Let us consider at this stage what is meant by “Value’. ‘Value’ is itself is somewhat difficult to define. It means different things to different people. Also, it is often confused with the cost and price of a product or service. One way of defining the value of an item is:

Value =Worth to you /Price you pay

This means that if you feel that you have your money’s worth, then you have received 100 per cent value. Which indicates that ‘Value’ has a subjective aspect, for what is good value for one person need not necessarily be so far another. In general, if for any function or a product or a service, you feel you are paying too much, or it costs you more than you think it should, there is scope for improving its ‘value’ into it. This leads us on to another useful way of looking at ‘value’.

Value is the least cost that can accomplish reliably a function or a service. This implies that in achieving reduced cost, the quality and performance of the item are maintained. It follows, therefore, that value analysis is a technique which builds “Value’ into an item.Value can also be defined as that combination of quality, efficiency price, and service which ensures the ultimate economy and satisfaction of the purchaser.

Value Analysis can be understood as a technique which helps everyone to determine this combination.It can be seen, therefore, that several components make up ‘Value’. There is value arising from the function or end use of an item, and from its ability to perform a useful function reliable. There is the subjective aspect of value in terms of esteem or prestige value or artistic value,

Finally, there is the resale or exchange value which may be taken as the ability to part with money for possessing a particular product. In addition we have place value with regard to the usefulness of a product at a particular place.

5 COMPANIES THAT IMPLEMENTED VE ARE:-

Ashok Leyland

Changed gear material from phosphor bronze to a less costly cast iron and eliminated frequent field complaints of gear seizure in trucks.

TVS

TVS used VE Approach to restore the mobility of buses that had broken down ,by stocking their garage with some critical assemblies and replacing them as in when needed thus enhancing mobility.

Modi Xerox

Designed the VE-d low cost copier 1025ST which uses a single tray. Easy to operate and lost cost.

ITC Welcome group

Implemented time-guaranteed room service strategy to enhance customer satisfaction.

TITAN

Introducing new designs by adopting a strategy of Innovation.

Q3. Explain different types of quantitative Models, Differentiate between work study and motion study?

Ans:

 There are different quantitative models.

1.     LINEAR PROGRAMMING: Linear programming technique is often used for optimizing a given objective like; profit or revenue maximization, or cost outgo minimization. Distribution of the revenues is the critical issue, when there are limited resources and they have to meet competing demands.

2.     TRANSPORTATION MODEL: Transportation model is concerned with goods from manufacturing centers or warehouses which have to be supplied to depots or retails outlets. The demand and supply position of the places where they are required or produced and the cost of transportation are considered in the model. We use this model to economize.

3.      ASSISGNMENT MODEL: Allocating jobs or persons to machines, awarding different projects to contractors is done so that maximum returns occur or less expenses are incurred. Hence, calls for the use of this model.

4.     INVENTORY CONTROL MODEL: Inventory control model considers the:·        Frequency of placing orders.·        Quantities per order considering the cost of placing an order.·        Number of pieces that are to be kept in reserve.·        Rate of consumption.·        Lead time required for the supplier.·        Cost involved in storage.We have different models which give solutions to optimization depending upon the probabilities of consumption and supply.

5.     WAITING LINE MODELS: Queues are formed when the rate of services is at a variance with the rate of arrival. They are formed when the rate of production is less at particular points compared to the previous one. Sometimes we see multiple service points and a single queue are formed for feeding them. Number of items which includes the following is studied with some special techniques.·        People to be serviced.·        Rate of service·        Type of queue discipline that is intended to be followed.·        Policy of priority·        Tolerable amounts of waitin·        Others.

6.     SIMULATION MODELS:  Simulation models are used when we will not be able to formulate mathematical model. So, we develop a model which resembles a real life

situation. Based on this pattern, we predict and plan our procurement, production, delivery and other actions.

7.     PERT (PROJECT EVALUATION AND REVIEW TECHNIQUE) AND CPM (CRTICAL PATH METHOD) MODELS: When projects are undertaken with a number of activities, some happens in sequence, with gaps of weeks or months and some happens simultaneously. It is important to estimate the time required for completion of the project. A lot of coordination is needed while supplying the resources. It is also equally important to identify the bottlenecks and smoothen resources so that time schedules are maintained. Delayed completion may entail penalties. In this model, we adopt special methods to make the system.

Q.4      what is rapid

prototyping? Explain the difference between automated flow line and automated assembly line with examples

Ans

Work study Motions study.

We can say that work study is being conducted when analysis of work methods is conducted during the period when a job is done on a machine or equipment.

Method study is on studying the method currently being used and developing a new method of performing the task in a better way.

The study helps in designing the optimum work method and standardization of the work method.

Operation flow charts, motion charts, flow process charts, which are the elements of the task are studied to find the purpose of each activity, the sequences in which they are done, and the effect of these on the work.

The study enables the methods engineer to search for better methods for higher utilization of man and machine and accomplishment of higher productivity.

The study may help in changing some of them and even eliminate some of them to effect improvements.

The study gives an opportunity to the workmen to learn the process of study thus making them able to offer suggestions for improved methods.

The new method should result in saving of time, reduced motions and simpler activities.

Rapid Prototyping (RP) can be defined as a group of techniques used to quickly fabricate a scale model of a part or assembly using three-dimensional computer aided design (CAD) data. What is commonly considered to be the first RP technique,

Stereolithography, was developed by 3D Systems of Valencia, CA, USA. The company was founded in 1986, and since then, a number of different RP techniques have become available.

Rapid Prototyping has also been referred to as solid free-form manufacturing; computer automated manufacturing, and layered manufacturing. RP has obvious use as a vehicle for visualization. In addition, RP models can be used for testing, such as when an airfoil shape is put into a wind tunnel. RP models can be used to create male models for tooling, such as silicone rubber molds and investment casts. In some cases, the RP part can be the final part, but typically the RP material is not strong or accurate enough. When the RP material is suitable, highly convoluted shapes (including parts nested within parts) can be produced because of the nature of RP.

 Prototyping is a process by which a new product is developed in small numbers.

Prototyping is helpful to:·         Determine the suitability of the materials·         Study the various methods of manufacture·         Determine type of machinery required·         Develop techniques to overcome problems that may be encountered when full scale

manufacturing is undertaken.

Prototype does meet the specification of the components that enter a product and performance can be measured on those. It helps in confirming the design and any shortcomings can be rectified at low cost. If serious defects or problems arise during manufacturing, a thorough change in design or even its replacement may be considered. Toa arrive at decisions and to make use of the advantageous stated above, it is important that the prototypes are made within the shortest possible time, Rapid prototyping facilities this.

The advanced Rapid Prototype Modelling Processes are:

Computer Aided Design (CAD)Selective Laser Sintering (SLS)Fused Deposition Modelling (FDM)Lamination Object Manufacturing (LOM)Electronic Beam Melting (EBM)

Difference between Automated Flow lines and Assembly Flow line.

AUTOMATED FLOW LINES ASSEMBLY FLOW LINES

Several Automated machines are linked by a transfer system.

All equipments are needed to in automated Assembly line

Handling machine have main role to move semi finished product to the

next stage.

All equipments make role of making sub-assemblies put together and fitted.

Semi-finished products are the main core activities.

Here Sub-assemblies product is the core activities.

Here raw materials are achieving to get required shapes and acquire

special properties.

Here intermediated products are achieving to get finished product.

The materials are needed to be moved, held, rotated, fitted and

positioned for completing different operations.

Here All parts or sub-assemblies are fitted to enables the product to be in readiness to perform the function it was

designed to. This process is called assembly.

Human intervention may be needed to verify that the operations are

taking place according to standards.

No human intervention is needed, methodologies are framed to achieve the final result, basic principle is to fit

parts together and ensure linkages so that the functions are integrated and give out the desired output.

Q.5 Explain Break even Analysis and centre of gravity methods. Explain product layout and process layout with examples.

Ans

Break Even Analysis

Every manufacturing company will have three major contributors to cost;1.      Investments made for land, plant and machinery resulting in interest and depreciation.2.      Recurring expenses, which are not proportional to the quantity of production.3.      Variable costs, which are directly proportional to the quantity produced.

For our calculations, we combine the first two costs together and call them fixed costs. We call those costs that depend on the quantity of production as variable costs.We compare the total costs for different locations on estimated amounts per annum and select whichever locations costs the least. However we will have to consider the possible variations in production levels during the foreseeable time spans and take decision.

CENTRE OF GRAVITY METHOD.

Centre of gravity method is used mainly when;·         Transportation costs, either for distribution of products or collection of materials from different suppliers is the main criterion.·         Production rates are high.·         The volume and weights of materials that have to be moved are huge.·         Time taken either to receive materials from suppliers or delivery to customers is critical.It is better to locate the facility at such a place, which caters to the different points most optimally. The vital factor is the load, that is, number of items, or the weights that need to be moved from the central location to the existing or demanding point. We use this method when, both distance and load have to be considered for optimality in terms of costs.

PRODUCT LAYOUT

Product layout is also called as production lines or assembly lines. They are designed and laid out in such a way that only few products are capable of being manufactured or assembled. Materials flow through the various facilities. These use special machines to perform specific operations to produce only one product at one time. So, companies should set different set of machines for different products. Workers perform a narrow range of activities to complete the operations on the product as it moves in a flow line. The operation times, the sequence of movements and routing procedures are highly standardized to meet production requirements which are synchronized with many such products to complete finished goods to meets demands. Using special machines and implementing standardization in operations have many advantages which are listed below:

·         The skill required of the workers is low·         Supervision is minimal·         Training needs are smallPrecautions to be taken are:·         Constant check on the processes needs to be performed so that quality is assured.·         Corrective measures have to be implemented to avoid rejections, since, the quantities that get manufactured will be continuous.·         Check for the behavioral of the worker. As jobs are repetitive, workers tend to be bored and lose concentration. This may affect productivity and quality.Example:

Let us consider an example of a stainless steel manufacturing industry, in which the operations turning, milling and drilling happen in a sequence. Testing is performed in each process to assure the quality. The items are then sent to the assembly block. The items that arrive for assembly are either bought out items or made item components from elsewhere in the plant. The final product inspection is made and sends to the packing dispatch.

TURNINGOPERATION

MILLINGMACHINES

DRILLING MACHINES

PACKING DISPATCH

INSPECTION ASSSEMBLY

Q.6 Explain Juran’s Quality Trilogy and Crosby’s absolutes of quality. List out the pillars of Total Productive Maintenance.

Juran’s quality trilogy

Juran uses his famous Universal Breakthrough Sequence to implement quality programs. The universal breakthrough sequences are:

1. Proof of need: There should be a compelling need to make changes.2. Project identification: Here what is to be changed is identified. Specific projects

with time frames and the resource allocation are decided.3. Top management commitment: Commitment of the top management is to assign

people and fix responsibilities to complete the project

4. Diagnostic journey: Each team will determine whether the problems result from systemic causes or are random or are deliberately caused. Root causes are ascertained with utmost certainty.

5. Remedial action: This is the stage when changes are introduced. Inspection, testing, and validation are also included at this point.

6. Holding on to the gains: The above steps result in beneficiary results. Having records or all actions and consequences will help in further improvements. The actions that result in the benefits derived should be the norm for establishing standards.

Juran has categorised cost of quality into four categories:

1. Failure costs – Internal: These are costs of rejections, repairs in terms of materials, labour, machine time and loss of morale.

2. Failure costs – External: These are costs of replacement, on-site rework including spare parts and expenses of the personnel, warranty costs and loss of goodwill.

3. Appraisal costs: These are costs of inspection, including maintenance of records, certification, segregation costs, and others.

4. Prevention costs: Prevention cost is the sequence of three sets of activities, Quality Planning, Quality Control, and Quality Improvement, forming the trilogy to achieve Total Quality Management.

Crosby’s absolutes of quality:-

Like Deming, Crosby also lays emphasis on top management commitment and responsibility for designing the system so that defects are not inevitable. He urged that there be no restriction on spending for achieving quality. In the long run, maintaining quality is more economical than compromising on its achievement. His absolutes can be listed as under:

1. Quality is conformance to requirements, not ‘goodness’2. Prevention, not appraisal, is the path to quality3. Quality is measured as the price paid for non-conformance and as indices4. Quality originates in all factions. There are no quality problems. It is the people,

designs, and processes that create problems5.

Crosby also has given 14 points similar to those of Deming. His approach emphasises on measurement of quality, increasing awareness, corrective action, error cause removal and continuously reinforcing the system, so that advantages derived are not lost over time. He opined that the quality management regimen should improve the overall health of the organisation and prescribed a vaccine.

The ingredients are:

1) Integrity: Honesty and commitment help in producing everything right first time, every time2) Communication: Flow of information between departments, suppliers, customers helps in identifying opportunities3) Systems and operations: These should bring in a quality environment so that nobody is comfortable with anything less than the best.

Quality Tools:-

1. Cause-and-effect diagram  (also called Ishikawa or fishbone chart): Identifies many possible causes for an effect or problem and sorts ideas into useful categories.

2. Check sheet:  A structured, prepared form for collecting and analyzing data; a generic tool that can be adapted for a wide variety of purposes.

3. Control charts:  Graphs used to study how a process changes over time.4. Histogram:  The most commonly used graph for showing frequency distributions,

or how often each different value in a set of data occurs.5. Pareto chart:  Shows on a bar graph which factors are more significant.6. Scatter diagram : Graphs pairs of numerical data, one variable on each axis, to

look for a relationship.7. Stratification : A technique that separates data gathered from a variety of sources

so that patterns can be seen (some lists replace “stratification” with “flowchart” or “run chart”).