This is to certify that the thesis "Computer simulation to assist improved MRP integration in MRP II system" being submitted in partial fulfillment of the requirement for the award of the degree of `Bachelor of Technology’ in `Mechanical Engineering’ by Mr. Anuj Agarwal is a bonafide work carried out under my supervision. To the best of my knowledge, the reported work is original and has not been submitted else for the award of any degree or otherwise

Dr. Subhash Wadhwa
Department of Mechanical Engineering
I.I.T Delhi

I express deep sense of gratitude to my guide Dr. Subhash Wadhwa, without whose untiring efforts and encouragement the project would not have been initiated.

I Semester (1997-98)

• Till Minor I: Learning about MRP II using CAFIMS. Understanding of the basic concepts and factory visits to know the problems being faced by Timex.
• Minor I - Minor II: Learning about the use of simulation in manufacturing. Understanding the working system in the Firm by regularly interacting with the Firm's management. Identification and clear definition of the problem and our area of focus. System Analysis leading to identification of alternative approaches. Data Collection and Information gathering.
• Till Major: Development of prototype MRP simulation model to illustrate the approach. Implication of collected data on prototype MRP model. In depth analysis of further requirement
• After Majors: Factory visits to understand the working MRP software used there. Interaction with PPC department for software analysis.

 II Semester (1997-98)

• Till Minor I: Detailed description of the functionality enhancement on the present MRP and its integration with MPS. Development of software with proper interaction with the end-users.
• Minor I - Minor II: Software Development and Verification with the firm. Simulation of alternative scenarios.
• Till Major: Presentation and discussion of results with the company. Preparation of final report.

Slight modifications may be made as per the Firm's insistence or Guides directive

The integration of planning and control functions and the day to day decision making is a common problem faced by the industry. The present manufacturing environment demands a high degree of flexibility and minimum lead-time from product requirement to delivery. To achieve the same complicates the decision making process for any workshop supervisor to fulfill the changing mix requirements and optimize the use of resources at the same time.

The project aims to solve a similar problem by integrating, simulation based MRP system with the existing system at TIMEX Watches Ltd. Company has a fast changing environment and key problem areas are high WIP and lead-time. Present decision making is intuitive, based on past experience. Our motivation is to support intuitive judgement by incorporating simulation based MRP within the existing system. This requires complete understanding of the system, together with data collection. Development of a prototype MRP simulator is in progress, which will be used as a functionality extension afterwards. We will try to evaluate the implication of uncertainties on the performance measures by simulating them, given priorities to certain class of products, lot size etc thus integrating the planning and control functions of the company.

 Keywords: Integration, MRP, Simulation, WIP, Lead-time, and Intuitive

• Certificate
• Acknowledgement
• Work Progress Schedule
• Abstract
•  Nomenclature/Abbreviations

Chapter 1 Introduction 1.1 Introduction 1.2 Traditional Production and Planning 1.3 Problems with Traditional Production and Planning	Chapter 2 Review of Literature and Statement of Problem 2.1 Introduction to the Manufacturing plant 2.2 Literature Review 2.3 Statement of Problem	Chapter 3 Progress to Date 3.1 System Analysis 3.2 Case Plant 3.3 Dial Section
Chapter 4 The GRAI approach 4.1 Introduction 4.2 Things to keep in mind	Chapter 5 Conclusion and Future Works 5.1 Conclusions 5.2 Future Works	References

• MRP: Material Requirement Planning
• MRP II: Manufacturing Resource Planning
• SFC: Shop Floor Control
• PPC: Production Planning and Control
• DSS: Decision Support System
• PAC: Part Assembly Cell
• FAC: Finished Assembly Cell
• CRP: Capacity Requirement Planning
• WIP: Work in Process

1.1 Introduction

With the world of economy developing fast and productivity norms being the focal point in the industries, the role of management to use the resources effectively becomes more and more crucial. It is virtually impossible to find an organization that does not either use, transforms and distributes or sells material of any kind. Traditionally materials were thought of as a cheap, readily available and plentiful. But with the changing concept the realization of cost effectiveness of products in global market and their proper management becomes an important feature. Materials management has tremendous influences on the ultimate cost of a product because it handles the total flow if materials in an organization. The total flow can extend from supply production and subsequently through distribution centers to customers.

1.2 Traditional Production Planning and Control

1.2.1 Forecasting

The forecasting function is concerned with projecting or predicting the future sales activity of the firm's products. Sales forecasting are often classified according to the time horizon over which they attempt to estimate. Long range forecasts look ahead five years or more and are used to guide decisions about plant construction and equipment acquisition. Intermediate range forecasts estimate one or two years in advance and would be used be used to plan for long lead-time material and components. Short-term forecasts are concerned with three to six month futures. Decisions on personnel, purchasing, and production scheduling would be based on short term forecast.

1.2.2 Production Planning

It's objective is to establish general production levels for products group over the next year or so. It is based on the sales forecast and is used to raise or lower the inventories, stabilize production over the planning horizon, and allow the launching of new products into the company's product line. Aggregate production planning is a function that precedes the detailed Master Production Schedule (MPS).

1.2.3 Process Planning

Process planning involves determining the sequence of manufacturing operations required producing a certain product and/or its components. Process Planning has been traditionally been carried out manually, prepared be hand and called `route sheet'. It is a listing of the operations and machine tools through which the part or product must be routed.

1.2.4 Estimating

For purpose to determine prices, predicting costs and preparing schedules, the firm will determine estimates of the manufacturing lead time and production costs for its products. The manufacturing lead-time is the total time required to process a workpart throughout the factory.

The production costs are the sum of the material costs, labor costs and applicable overhead costs needed to produce the part. These estimates of lead-time and costs are based on data contained in the route sheets, purchasing files, and accounting record.

1.2.5 Master Scheduling

The aggregate production plan must be translated into a master schedule which specifies how many units of each product are to be delivered and when. In turn, this master schedule must be converted into purchase orders for raw materials, orders for components from outside vendors, and production schedules for parts made in the shop. These events must be timed and coordinated to allow delivery of the final product according to the master schedule.

Specifically, the master schedule or master production schedule is listing of the products to be produced, when they are to be delivered, and in what quantities. The scheduling period in the MPS are typically months, weeks, or dates. The MPS must be consistent with the plant's production capacity. It should not list more quantities of product than the plant is capable of producing with its given resources of machine and labor.

1.2.6 Requirement Planning (MRP)

Based on MPS, the individual component and subassemblies that make up each product must be planned. Raw material must be ordered to make the various components. Purchased parts must be ordered. And all these items must be planned so that the components and assemblies are available when needed. This whole task is called planning or material requirement planning (MRP). The term has evolved due to the introduction of computerized procedures to perform the massive data processing required to accomplish this function.

1.2.7 Purchasing

The firm will elect to manufacture some components for its products in its own plants. Other components will be purchased. Deciding between these alternatives is the familiar "make or buy" decision. For the components made in-house, raw material have to be acquired. Ordering the raw material is the function of the purchasing department. Materials will be ordered and the receipt of these items will be scheduled according to the timetable defined during the requirement planning procedure.

1.2.8 Scheduling

Also based on the requirement planning activity is production scheduling. This involves the assignment of start dates and due dates for the component to be processed throughout the factory. Several factors make scheduling complex. First, the number of individual parts and orders to be scheduled may run into the thousands. Second, each part has its own individual process routing to be followed. Some part may have to be routed through dozens of separate machines. Third, the number of machines in the shop is limited, and the machines are different. They perform different operations and have different features and capacities.

The total number of jobs to be processed through the factory will typically exceed the number of machines by a substantial margin. Accordingly, each machine, or work center, will have a queue of jobs waiting to be processed. Allocating the jobs to work center is referred to as machine loading. Allocating the jobs to the entire shop is called shop loading.

1.2.9 Quality Control

The quality control department is responsible for assuring that assuring that the quality of the product and its component meets the standard specified by the designer. This function must be accomplished at the various points throughout the manufacturing cycle. Materials and parts purchased from outside suppliers must be inspected when they are received. Parts fabricated inside the company must be inspected, usually several times during data processing. Final inspection of the finished product is performed to test its overall functional and appearance quality.

1.2.10 Inventory Control

The purpose of the inventory control is to ensure that enough products of each type are available to satisfy customer demand. Competing with this objective is the desire that the company's financial investment in inventory be kept at a minimum. Inventory control interfaces with production control since there must be coordination between the various products sales production and inventory level. Inventory control is often included within the production control department.

The inventory control function applies not only to the company’s final product. It Laos applies to raw material, purchased components and WIP (work in progress) within the factory. In each case, planning and control are required to achieve a balance between the danger of too little inventory) with possible stockouts) and the expense of too much inventory.

1.3 Problem with Traditional Production Planning and Control

Various Problems are as follows:

• Plant capacity problem
• Suboptimal production scheduling
• Long manufacturing lead times
• Inefficient inventory control
• Low work utilization
• Process planning not followed
• Errors in engineering and manufacturing records
• Quality problem

2.1 Introduction to the Manufacturing Plant

The Firm is into Watch Manufacturing. It is a multinational firm with tie-ups with local watch manufacture looking after its marketing. The firm manufactures a wide variety of components. The firm alone produces around 350 different watch models every year.

Initially the firm was into Plastic watch models but now it is starting to venture out in metal watches too. There are around 40 different components in a single watch of which around 10 is imported. The demand of the watches is varied and product mix to be manufactured is almost different every month. Capacity of the firm is around million watches per year.

This is important to note that the manufacturing time of the sub assemblies, which make the end product, is negligible as compared to the lead times of the raw materials. The set up time for switching over from one model to another is also less. The manufacturing facility at the firm has got a large warehouse which holds very high inventory level and thus high in built capital. Reduction in the inventory to the minimum is the prime target of the materials department.

At TIMEX real time controls using parts priority is a common practice. In addition to the scheduling complications, the departmental mangers cannot give a proactive feedback about the implications of the changes in the already existing plan to the PPC department. Thus keeping all these complexities in mind, development of macro analytical model would be impractical and simulation of the shop is seen to be the best way of analyzing the shop.

2.2 Literature Review

2.2.1 Decision support system

Decision support system refers to a class of systems, which support the process of decision making. The emphasis is on support rather than automation of decisions [2]. Decision support system allows the decision-maker to retrieve data and test alternative solutions during the process of problem solving. The typical characteristics of DSS are as follows [1]:

• Assists the manager to decision process
• Supports and enhances managerial judgements
• Improves decisions making effectiveness
• Assures interactive problem solving

2.2.2 Computer Integrated Production management System

Various factors working over the last several decades to cause the evolution of a more modern and effective approach to the problem of production planning and control towards computerization were [5]:

• Increase in the level of production professionalism
• Development of better production planning
• Increase in the complexity of both the products manufactured and the markets to buy these.
• Development of the techniques of the operations research

2.2.3 Material requirement planning (MRP)

MRP involves determine when to order raw materials and components for assembled products. It can also be used to reschedule orders in response to changing production priorities and demand conditions. The term priority planning is now widely used in describing computer based systems for time phased planning of raw materials, WIP, and finished goods [5].

MRP is a computerized technique that converts the master schedules for the end product into detailed schedule for the raw material and component used in the end product.

MRP is often considered to be a subset of inventory control. While it is an effective tool for minimizing unnecessary inventory investment, MRP is also useful in production and purchasing of materials. Basic MRP structure is as shown in Fig. 1

2.2.4 Benefits of MRP

Various benefits of MRP are as follows [5]:

• Reduction in inventory
• Improved customer service
• Quicker response to change in demand and in master schedule
• Greater productivity
• Reduced set-up and product changeover costs
• Better machine utilization

 2.2.5 Inputs to MRP

MRP converts the MPS into the detailed schedule for raw materials and components. For the MRP program to perform this function, it must operate on the data contained in the MPS. However this is only one of three sources of input data on which MRP relies. The three inputs are [5]:

1. The master production schedule and other order data.

2. The bill-of-material file which defines the product structure

3. The inventory record file

2.2.6 MRP output reports

Various Output reports generated by MRP are [5]:

1. Order release notice
2. Reports showing planned orders to be released in future period
3. Rescheduling notices, indicating changes in due date for open orders
4. Cancellation notices indicating the cancellation of open orders because of MPS
5. Reports on Inventory status
6. Performance reports of various types, indicating costs, item usage, actual versus planned lead times, and other measurement of performance
7. Deviations from schedule scrap overdue orders etc.
8. Inventory forecasts, indicating projected inventory level in future period

2.2.6 Inventory Management

Inventory control is concerned with achieving an optimum balance between two competing objectives. The objectives are first, to minimize investment in inventory, and second to maximize the service levels to firms customers and its own operating departments.

Inventory types and general control procedure [5]

There are four types of inventory with which a manufacturing firm must concern

1. Raw material and purchased components

2. In-Process inventory

3. Finished Product

• Maintenance, repair, and tooling inventories

To manage these various kind of inventories, two alternative control procedures can be used [5]:

1. Order point systems

2. Material requirement planning (MRP)

2.2.7 Evolution of Manufacturing Resource Planning (MRP II)

MRP II is nothing but link up between closed loop MRP and financial system of the company. Closed loop MRP means that the various functions in production planning and control (capacity planning, inventory management, shop floor control, and MRR) have been integrated into a single system. It also means that there is a feed back from the vendors, the production shop and so on, when problems arise in implementing the production plan [5].

MRP II possesses two basic characteristics, which go beyond closed loop MRP

• It is operational and financial system
• it is simulator

The operational and financial system makes MRP II a company wide system, concerned with all facets of bushiness, including sales, production, engineering, inventories, and cash flow. In all cases, the operations of the individual departments are reduced to the same common denominator: financial data. This common base provides the company management with the information needed to manage it successfully.

MRP II is also a simulator, which is intended to answer "what if" questions [5]. The simulator can be used to simulate the probable outcomes of alternatives production plans and management decisions, which are under consideration.

2.2.8 Simulation and Modeling

Simulation is a technique of imitating the behavior of some situation or system by means of analogous situation, a model or apparatus, either to gain information conveniently or to train personnel [6]. The development of the model and the use of simulation provide feeling, insight and opportunity to operate and manipulate a system [4]. For dynamic problem involving real time control through diverse priority rule changes, analytical formulation is not possible. Thus actual simulations of the shop can help give reasonably good schedules in a short time. Computer simulation refers to techniques for using computers to imitate the operations of various kinds of real world facilities or processes. This process or facility of interest is usually called a system and in order to study it scientifically, one often makes a set of assumptions about how t works. These assumptions which usually take the form of mathematical or logical relationships constitute a model that is used to gain understanding of how the corresponding system behaves.

 2.3 Statement of Problem

The Watch industry has a very unpredictable demand pattern. This is because of introduction of new watch models periodically. Each year the company replaces ¼ th of its model range to introduce new models. Many a times it happens that there is a fall in the demand of a certain item, but by the time the Firm knows the demand pattern, it already has produced a sizeable inventory keeping in mind the previous pattern. This results in build up of unwanted finished product inventory. It can happen vice versa too i.e. the demand is more but the production is less. Company suffers huge losses owing to this. The company is using all its past experience in forecasting. While there is always a scope to improve any forecasting model, the company is keener to determine an approach to deal with the problem through an improved integration between its production planning and control functions. One of the areas of interest is to extend the functionality of MRP to provide better response against unplanned changes in demand.

Moreover the company has the unwanted inventory piling up. It has huge amount of raw material inventory to assemble variety of models, but still it has to purchase more raw materials to produce even the next day assembly model. Company is losing significant amount of resources on this unwanted inventory. A better integration between master production scheduling and MRP is required. This can improve the material management also. The vital 20% of the raw product is being neglected. The company may benefit by extending the functionality of MRP and its integration with production planning. We envisage that this will require simulation of alternative approaches to select best approach. Refer Fig 2

 There are various uncertainties in the present system due to which the plans are not strictly adhered to. Many a times there is immediate demand of a certain item due to which the on going production is postponed. This results in the unwanted increase in the WIP of a certain material. We plan to introduce `What-If’ analysis do that the forecasted production plans can be overviewed and certain decisions based on that taken. The emphasis is on `support' rather than automation of the decisions. This allows the decision-maker to retrieve data and test alternative solutions during the process of problem solving. The main payoff for support is where the decision-maker’s insight and judgement are needed to control the process. This effective problem should be interactive and is enhanced by a dialog between the user and a system. Refer Fig. 3

3.1 System analysis

The project was taken up at TIMEX Watches. First of all to tackle the problem we had to understand the process and plant layout. Moreover in depth study was taken so that each process was clearly understood, and there importance with respect to production. There were some sections, which serve as the bottlenecks. Our aim was to fully comprehend their utility.

3.2 The Case Plant

The case plant was setup keeping in view the production control system and the monitoring of all the production processes and the entire material flow. It was also meant to serve as a vital aid in decision making for the concerned Industrial Managers. The information technology has been judiciously used for the vital information flow. The material and the production system are highly complex in the Case plant. The highly complex material flow and the large quantities involved made it virtually impossible for the concerned manager to keep a track of the details of the production system. Consequently, at times not only would the decisions being taken by the concerned person be without accurate information but also grave errors of planning would result in the disruption of the production system. To make matters worse, the production flow includes other sections of the company (such as Ion Plating) and also several Vendors (Like Buffing and Polishing), which not being a part of the case plant are very difficult to monitor and account for.

The need for monitoring of the inventory was

• to know the exact status of the inventory on hand
• to decrease the Lead times of the components
• to decrease the WIP

3.2.1 Production System

The Case plant is divided into various sections

• Press shop: Machines - Three 63 ton Presses, One 100 tonne Press, Four Hydraulic Presses, Annealing furnace, Deburring machines. The various Bezel Casebacks, Plastic casebacks and Bezel Ring lots start here. After the initial operations of Piercing and Blanking the various Forging operations are also here on the Hydraulic Presses. For casebacks blanking operation is also done here.
• Machine shop: Machines - Seven SAT machines. Two CNC lathe machines, Two Petermann machines for manufacturing crowns. Several special purposes machine for various operations such as Pendant Hole Boring and Reaming etc. The machine operations are done on the Bezels, Caseback sand Bezel Rings in this shop. Crowns are manufactured on the two Petermann presses.
• Case Assembly: Assembly apparatus, Hormec Testing machines, Press fits. In this shop the Bezels are combined with casebacks alongwith other relevant components like Pendant Pipes, Crystals, etc to form the Case Assemblies. In these Case Assemblies which are turned in to the main store.

Other production sections relevant to the functioning of the Case Plant are:

• Vendors: The Bezel and Casebacks are sent to the vendor for the Buffing and Polishing. These being out of the plant, comprise a major difficulty in the development of a successful Production control system
• Ion plating section: After the Bezels return from the vendors, the Bezels marked for Plating are sent to the Plating Section for Gold Plating. Everything is done In house

The Case Plant has its own QC section which conducts sampling tests on the various lots offered to it for Lot inspection and accepts/rejects the various lots. It also monitors the various in - process checks being done by the operators and provides them with relevant details about the checks to be made. The QC lot inspection can be done at any of the following stages

• After Press Shop
• After Machine shop
• After Vendor
• After Ion Plating
• After Case assembly and before Turn-in

The Case plant has its own stores where the tools and the components are stored. The store is divided into two parts

1) Tool Crib - where the various tools are stocked

2) Material Store - where other components are stocked. The Material Store deals with the Material movement in and out of the Case plant is dispatch to vendors, receipt of the material from vendor, dispatch to and receipt from the Ion planting an Turn-In to the main store. The Tool-crib deals with the issuance and return of material or tools.

3.2.2 Products Manufactured

The Case plant manufactures a large range of metal parts for watches. These include the following

• Bezel or Case backs
• Snap Fit Casebacks
• Flat type Casebacks for Plastic Cases
• Crowns
• Bezel Rings
• Spacers

3.2.2.1 Lot numbering system for Case Plant

Format `----\---\--‘

• First two digits are the month number (01 to 12)
• The next two digits are the year (do not write century)
• The next three digits are the model reference number
• The last two digits comprise the lot number of the specified lot for the given model, month, and year (01-99)

The types of model which are turned in to the Main stores are Case assemblies (SS and GP), Spacers, Crowns and Flat Casebacks. Other types of models are various parts for some other types and are not turned in but are transformed into a different type of model by

• Assembly (as in the case of a GP/SS Bezels, Casebacks, Bezel Ring and Crowns)
• Plating (as in the case of SS Bezel being converted into a GP Bezel)

The shops that the various types of model go through (in order) are: (Fig 4)

• Bezel: Press shop à Machine shop à Vendor à Ion Plating à Case Assembly
• Caseback: Press shop à Machine shop à Vendor à Press Shop à Case Assembly
• Flat Casebacks: Spacer à Press Shop
• Crown: Machine shop
• Bezel Ring: Press Shop à Machine shop à Case Assembly

 3.3 Dial Section

This explains the various shop functions of the dial shop at TIMEX. An overview will be given of the various dial styles and the various manufacturing processes through which they pass. Subsequently there is mention of some of the characteristics of the dial shop.

The dial shop at TIMEX produces approximately 2 lakh dials every month. There exist more than 350 styles requiring different machining sequences. The quantity in which these dials are produced varies monthly from style to style and within the same style, it varies from month to month. Every month around 5-10 new styles are introduced and about the same number are phased out. The raw material comes in the form of long strips, which are cut to the specific size and then taken for further processing. Based on the machining sequence the styles can be broadly classified into the following categories:

• Plain Printed Dials
• Embossed Dials
• Applique Dials

The process sequence for each type is as follows:

Plain Printed Embossed Applique

Crop to length Crop to length Crop to length

Pierce and Notch Pierce and Notch Pierce and Notch

Straightening Window Piercing Blanking

Blanking Embossing Bumping

Pin Welding Blanking Pin Welding

Printing Restriking Drilling

Lacquering Applique Fixing

Faceting Printing

Pin Welding

Printing

There are various styles of dials within which each of the above mentioned categories that do not follow the above-mentioned schedule. Some may skip a few operations, others may do the operations in a different order and some have other operations.

The Operations details are as follows:

• Crop to length: The raw material for the dial comes in the form of long stripes, which are cut to a particular size. This operation is done for all styles.
• Pierce and Notch: The strips obtained from the above operations are notched at the edge to facilitate movement of the strip in subsequent operations
• Embossing: To get projections on the dial surface the dial is embossed by pressing an embossing insert onto it, creating an impression on the dial.
• Blanking: The dials are finally cut out of the strip in this operation. Different dials may be of different sizes and shape
• Faceting: The projections obtained in the embossing operations are given surface grinding using a diamond tool.
• Restriking: Faceting tend to smooth out the projections. The repetition of embossing is called Restriking.
• Straightening: The raw material is in the form of long strips rolled on the spool. This operation is done to remove the curving that takes place.
• Bumping: In this operation each dial is straightened separately. This is done after the blanking operation
• Drilling: Applique dials must have holes for fixing the inserts. These are drilled in the dial.
• Grooving: This operation is done to make groove on the dial when required. It is done on the drilling machine itself.
• Applique fixing: The applique dials are made by fitting inserts onto the dial. This is done manually
• Pin Welding: The dial is attached to the movement of the watch via two pins diametrically opposite. These are resistance welded onto the dial.
• Window Piercing: Styles of watches having Day and Dates facility need n extra window for this in the dial
• Lacquering: To maintain fine finish on the surface of the dial, a solution is applied onto it.
• Nickel Plating: This operation may need to be done to give some styles on dials a particular surface color finish
• Printing: Every dial requires to be printed with some design. A dial may have between one and five prints.

3.3.1 Characteristics of the Dial Shop

The dial section engaged in producing more that 350 styles of dials has each of its dials requiring different machining operations and sequence. The shop gets a monthly plan from the PPC department, which is subject to change weekly. Sometimes even the day to day plans are provided by the PPC, in case of rush orders. Some important aspects of the shop that are essential for understanding the system are enlisted:

• The shop operates as a general job shop system

• Processing time per component are negligible to setup time of the lots

• Same tools and fixtures for various dials on the same machines

• Parallel machines in the system
• Usually 8-10 dial lots operate in the system
• Different machines may operate for different number of shifts

4.1 Introduction

GRAI approach tells us about the process by which information system should be embedded in the decision system. By focussing on both the systems simultaneously one can arrive at the better solution. We go about the GRAI approach in a sense that information on hand is used to support the decision system. This gives a more holistic view of the picture. Refer Fig. 5 [7]

 Information system should be embedded at each level so that decisions being made at that level are made in lieu with the on-hand information. Fig. 6 [7] describes coordination of physical system with information and decision system. Physical system comprises of raw material components, finished products, WIP etc. This acts with the decision system for purchase orders, reorder levels etc. The decision system interacts with the on-hand information. All this is required in our case because most of the decisions are being done intuitively. If we also incorporate the information part it will be beneficial for taking the right decisions.

 4.2 Other things to keep in mind

We should also keep in mind certain other things. Due to forecasting errors there is huge amount of final product that goes waste. By the time the consumer demand reaches the company the actual demand for that product has changed. This results in built up of unwanted finished product and time wastage. If one can capture the actual consumer demand, one can expect huge profit margins and reduced WIP. If the model incorporates these unforeseen fluctuations then it is in better position to catch the best demand trend. Refer Fig 7 [7] and Fig 8 [7]

 The top management has to consider the limitations of the operational level. The CRP analysis should be done precisely so that there is no overestimation or underestimation. Refer Fig. 9 [7]

5.1 Conclusions

Our main aim was to determine the trouble areas at TIMEX and come up with a basic MRP model. Final points are as follows:

• Company has fast changing environment
• Key problems are high amount of WIP, and high lead-time
• Presently most of the decisions are done intuitively
• Present MRP doesn’t support simulation
• Development of a Prototype MRP model

5.2 Future Works

• Motivation to support Intuitive judgement
• Functionality enhancement of MRP model
• Simulated MRP embedded in present MRP model at TIMEX