Claro Publications Private Limited Claro: Journal of Engineering
Research Article CASE STUDY ON MANUFACTURING RESOURCE PLANNING Janakkumar Tanna*a , Ankur Vyas*b *a
K. J. Institute of Engineering & Technology, Savli, Asst. Prof., Faculty of Engineering, Mechanical Engineering Department, Gujarat, India- 391770 *b K. J. Institute of Engineering & Technology, Savli, Asst. Prof., Faculty of Engineering, Mechanical Engineering Department, Gujarat, India- 391770
Abstract The gap between Manufacturing Resources Planning (MRP II) system and the Flexible Manufacturing System (FMS) and discuss several approaches for closing the gap. Considerable effort has gone into developing and integrating the various modules in the MRP II system. The modules for business planning, production planning, master production scheduling, material requirement planning, capacity requirements planning, and shop or control have been integrated into a comprehensive computer package for planning and controlling manufacturing. At the same time, a similar effort has been underway to develop and integrate the several subsystems of a FMS. In particular, a number of computer control systems have been developed to automatically plan and control the operations of NC machines with automated tool changers, automated material handling, and automated test and inspection equipment. Unfortunately, these two efforts have proceeded relatively independently with little interaction between the two groups. If computer integrated manufacturing (CIM) is to become a reality, the resulting gap must be closed, and closed rapidly. Material Requirements Planning is a time phased priority-planning technique that calculates material requirements and schedules supply to meet demand across all products and parts in one or more plants. Information Technology plays a major role in designing and implementing material requirements planning systems and processes as it provides information about manufacturing needs (linked with customer demand) as well as information about inventory levels. MRP techniques focus on optimizing inventory. MRP techniques are used to explode bills of material, to calculate net material requirements and plan future production.
Keywords - MRP, MRP II, ATP, PAB, MPS, BOM I.
INTRODUCTION
Material requirement planning is use for mainly material management purpose during product life cycle in company. It is good to handling purchase, warehouse, inventory and many more. In this, project included part of material management for a department. In brief, process steps for material for flow, material requirement with each sub-department data.
eeng-37-2017
MRP has become a general term used to describe material requirements planning, closed-loop MRP and manufacturing resource planning (MRP II). The advent cheap computing power in the 1950s and 1960s led to a rapid growth in number of companies using MRP. After accounting and payroll systems, MRP was earliest computer applications to become wide spread. MRP offered companies the ability to order goods according to actual requirements, rather than simply replenishing standard stock levels. Initially, MRP was used mainly purchased items followed, especially in those factories where there was irregular demand and wide range of items, such as in aerospace industry. According to Browne et al. (1988), MRP and MRP II have been the most widely implemented large scale production management systems since 1970s, with several thousand implementations worldwide. MRP has become a general term used to describe material requirements planning, closed-loop MRP and (MRP II). The advent cheap computing power in the 1950s and 1960s led to a rapid growth in number of companies using MRP. After accounting and payroll systems, MRP was earliest computer applications to become wide spread. MRP offered companies the ability to order goods according to actual requirements, rather than simply replenishing standard stock levels. Initially, MRP was used mainly purchased items followed, especially in those factories where there was irregular demand and wide range of items, such as in aerospace industry. According to Browne et al. (1988), MRP and MRP II have been the most widely implemented large scale production management systems since 1970s, with several thousand implementations worldwide. In paper, MRP Sheet concerns with MRP I and MPS sheet says about MRP II.
Finally, C, C++ programming give easy way for input of MRP I and MRP II. Open ERP is good software for flow handling in any module of Manufacturing Resource Planning.
Corresponding author: Tel: 979271267, +91-2667-222264 E-Mail:
[email protected]
+91-9624808101,
+91-
1
Claro Publications Private Limited Claro: Journal of Engineering MATERIAL REQUIREMENT PLANNING Simple Material Requirement Planning: Time Phasing:MRP is phased order release system that under ideal circumstance schedule the order release for needed demand inventory items so that the items arrives just as they are required. MRP calculate the date upon which an item may be ordered either from factory or from supplier, by reference to the date on which the items needed and items arrive. The simple operation which is manually for limited number of items. MRP requires backward scheduling each item from its requirements date to launch production and purchase orders accordingly so that they will be completed on time. The main item MRP uses is lead time. Example:All components of 50 widgets are required for assembly at start of June, all parts have a lead time from order to delivery of one month, and then order must be released at the start of May. Further, all parts will have same lead time, but particular time for each item is stored in master file. The MRP software will release each work or purchase order from the parts list of each product the appropriate time before requirement date for each specific order. The files use for MRP system:Bill of material:The bill of material is a list of all purchase parts and raw material required to manufacture a finished product. It can be broke down in sub-assemblies which turn into require other purchase parts.
Figure 1 Master Production Scheduling:This file, as its name implies, store company plan of to manufacture and when. It is derived from order receives from customer and forecast orders. The accuracy of this file together with its efficient update required is fundamental to effectiveness of MRP system. Inventory Status File:The inventory status file keeps a record of amount of stock and usually stock transactions. As in the case of MPS, the accuracy of this file is critical. This is because when BOM is exploded and requirements for the next time period are calculated the amount in stock is subtracted from the gross amount required, giving the net amount required to be produced. Clearly, inventory status file will be incorrect then an incorrect amount will be manufactured. This can create excess stock or shortage. Parts Master File/Item Master File:This file holds the information related to ordering each part. The file normally stores the standard batch size, lead time and stock categorization which part may have and sometime
eeng-37-2017
routing information. A separate file may be used for details of purchase parts. In some implementations the routing may be also use in the routing or process file. Routing File/Process File:For each manufactured items, this gives sequence of operations and work centers used. If infinite capacity planning was in operation then predicated or standard times for each operation would be stored here. Work Centre File:This file stores details about each work center, such as costs associated with it, standard set-up available on it. Tool File:This file can be used in connection with the work center file and the parts master file. It stores details about tools, jigs etc. which are required for particular operations. This allows the MRP to order tools required for a specific operation. Bill of Materials: Ordering is usually for items required to make up a product to satisfy a customer’s order, MRP systems almost invariably provide the means to store and manipulate the list of parts required for each product. This is generally known as the bill of materials. Inventory Management: Items held in stock under various different policies MRP systems almost always provide the ability to record details of current stock and items which are in stock but which are already allocated to be used for a particular customer, and which are not therefore available for use. Dealing with orders: The addition of these functions, where they are needed, makes for a set of repetitive clerical task which lends itself to being performed by computer. It is usually for MRP system also print out the actual paperwork which is sent to suppliers or to factory, transmits the information by electronics means, such as e-mail. Purchase orders may take a variety of forms according to the contractual agreement between customer and suppliers. Purchase orders to be print on multi-parts forms which carry standard set of purchase conditions. Delivery notes and invoice are used for tracking MRP. Batch Cards, Travellers, Route Cards, Dockets identify the items to be manufactured. It deals with manufacturing operations required, expected or allowed time, quantity requirements and quality requirements. Operations: CLOSE LOOP MRP Oliver Wight sums up meaning of ‘closed loop’: The term ‘close loop’ really has two meanings. It means that the missing elements in the system like capacity planning, shop scheduling and vendor scheduling were filled in the system. It also means that there must feedback from vendors, from the factory, from the planner, etc. whenever there is any problem in executing the plan. Capacity planning:Standard MRP system takes the finished good requirements and calculates the net material requirement. Closed loop system perform same MRP function but go on to produce capacity plan. The same plan attempts to show the load required on each work station during production period, weather be in month, week or day. The capacity plan is calculated by using the routing file to show the work load which will be generated at each work station by net requirements. This shows total expected set-up and run times for all the items to be produced during the period.
2
Claro Publications Private Limited Claro: Journal of Engineering Closing the loop:Closing the loop in MRP system involves providing the feedback about progress. Standard hours: It is time as per capacity plan and as per schedule hour work should be completed in appropriate manner. Closed loop systems also update the system lead times. The program may use calculate moving average which can be adjusted by each new figure. In plants that are always busy, this allows the lead time to get longer and longer. These increases queuing and incase of urgent shipment order may delay in some other work. This seems in failure in completion of order. By increasing lead times in response to increasing actual lead times the situation is worsened, not improved. Finite capacity planning system added, then progress on individual items can be scheduled and measured. MANUFACTURING RESOURCE PLANNING: Growing companies tend to develop systems to solve problems as they arise. The philosophy behind MRP II is centralization and coordination, allowing considering effort to be saved by everyone following the same system. Traditionally, accounting figures were not based on same information as manufacturing figures. For example, the accounts department would have separate from manufacturing to calculate the inventory. This was because the manufacturing information was not believed to be accurate for accounting purpose- it was prepared by engineer, not accountants. Production departments would often independently calculate the work in progress measured in terms of ‘standard hours’. Advanced user of closed loop MRP system realized that if the accuracy of inventory record good enough to support an MRP system then it would be good enough to support an MRP system then it would be good enough to be used financial purposes. This allowed the financial and production departments to work with the same, accurate, information thus allowing them to keep business plan up to date. The linking of financial and manufacturing system is main step in moving from closed loop MRP to MRP II. Meaning of Manufacturing Resource Planning (MRP II):Manufacturing Resource Planning (MRP II) is method for the effective planning of all resource of a manufacturing company. It is made up of variety of interlinked functions, as shown in such as: 1. Strategic and Business Planning. 2.
Demand Management.
3.
Sales and Operation Planning (S&OP, also called Production/Aggregate Planning).
4.
Master Production Scheduling (MPS) with Rough-Cut Capacity Planning.
5.
Material Requirements Planning (MRP I)
6.
Capacity Requirements Planning (CRP) and Vendor Requirements Planning (VRP).
7.
The Execution Support System for Capacity and Material [Shop Floor Control (SFC), and Purchase Planning and Control]
eeng-37-2017
Operational planning in sales units o
Financial planning in monetary units (for example in rupees or dollars etc.)
Further, an ideal MRP II system has simulation capacity to answer ‘what if’ questions.
Output from various report MRP II function is usually integrated with financial report such as financial plan, purchase commitment report, inventory projections.
MRP II often integrated with a warehousing and distribution processes.
company’s
MRP II is an approach to managerial planning, execution, and control of productive activity. MRP II software can relate many information needs of all functions and departments, including purchasing, accounting, payroll, distribution, marketing, engineering, production activity control and general managerial planning, measurement, evaluation and control. MRP II is an explicit and formal manufacturing information system that integrated marketing, finance and operations. It coordinates the sales and manufacturing plans to assure their consistency. It converts resource requirements, such as facilities, equipment, personnel, and material, into financial requirements and converts production outputs into monetary terms. It evaluate the organization’s ability to execute the plan financially and also evaluates the financial merits of plan in terms of measures as profit, returns on investment and return on assets. A Framework for the MRP II system:Following is overview of MRP II architecture which can divide into three hierarchical levels: Planning Level Planning Horizon Strategic Planning Tactical Planning
One to five years One month to three month
Operational Planning
Quasi-real time to one year
MRP II architecture shown in a situation where a factory has been subdivided into series of Group Technology based cells, where each cell is responsible for family of products, subassemblies or components and is managed by a Production Activity System (PAC) system.
3
Claro Publications Private Limited Claro: Journal of Engineering It forms basic inputs of MRP by top management and covers long time horizons. It includes overall planning of product.
MRP II encompasses three activities or phases: Master Planning: The first activity is establishment of the overall direction for the firm, the resulting management plan stated in manufacturing terms, such as end items or product options. The manufacturing plan must be consistent with the company’s direction and the plans for other departments of the firm. Thus, master planning is the set of activities and system for overall direction setting it creates overall plans stated in production terms.
Business plan is statement of objective for overall aspect at aggregate level. Sales and operational planning main area for planning in this element. The business plans defines: market share, new product planning, analysis of competition, distribution and strategic planning, product positioning to meet customer service objectives. The markets to be addressed (target demographic and geometric areas). Annual sales plan or forecast for overall business or particular Make or buy decision. 1.
Demand Management:
Demand management encompassing areas are: Advertising, forecasting, customer order services, distribution requirement planning. 2.
Sales and Operation planning:
It mainly related to demand of market and product structure planning. It is necessary to evaluate every time sales and operation planning in each stage. [1]
Detail Planning of material flows and capacity:
The second MRP II activity is the detailed planning of material and capacity needs to support overall production plans.
Business Planning:
Execution of plans:
The third and final MRP II activity is execution of material and capacity plans in terms of detailed shop scheduling and purchasing actions. Elements of MRP II: 1.
MRP I
2.
Strategic and Business Planning
3.
Resource Requirement Planning
4.
Demand Management
5.
Product Configuration
6.
Sales and Operational Planning
7.
Master Production Scheduling and Final Assembly Scheduling
8.
Rough Cut Capacity Planning
II. METHODOLOGY AND PROBLEM SOLVING Schematic of MRP shown in figure 1. PROBLEM ON MRP:This will be explained through an example of electronics calculator. Master Production Schedule Order For WEEK Calculator 23 24 25 26 27 Packed A 11 100 B 12 50 Bill of Material Calculator Packed Calculator Complete 1 Lower Case Assembly 1 Lower Case Molding 1 Battery Cover 1 Upper Case Assembly 1 Upper Case Moulding 1 Transparency 1 Circuit Board Assembly 1 Key Pad 1 Screw 3 Carton 1 Insert 1 Instruction leaflet 1
Strategic and Business Planning:
Strategic Planning:
eeng-37-2017
4
Claro Publications Private Limited Claro: Journal of Engineering Problem on MRP I:
Bill of Material explosion (Some items are not shown) Items Order Quantity Calculator Packed Calculator Completed Carton Circuit Board Assembly Keypad Lowe Case Assembly Screw Upper Case Assembly
A11 B12 A11
100 50 100
B12 A11 B12 A11 B12 A11 B12 A11 B12 A11 B12 A11 B12
50 100 50 100 50 100 50 100 50 300 150 100 50
Items Master File (Some Items are not shown) Items Lead Make/Buy Time Calculator Packed 1 M Calculator 1 M Completed Carton 3 B Circuit Board 4 B Assembly Keypad 4 B Lowe Case 1 M Assembly Screw 1 B Upper Case Assembly
eeng-37-2017
1
M
Summary of MRP information (Certain items only) Week 19-27
LT
On-hand Gross Net To-Order
Problem on Master Production Scheduling Report (With PAB and Regular ATP Calculation) It involves terms below:
The Lead Time: It is number of period required to manufacture or purchase time for an item. It is also called as cumulative time for components. It might be for a higher level of product or small level of product.
On-hand: It is quantity of this item in physically in stock.
Lot Size: It is quantity of this item normally ordered from the plant or supplier.
Safety Stock: Additional stock of these items planned to be in inventory as protection against unplanned demand.
Demand Time Fence: It is future master-schedule periods inside which changes to MPS are accepted due to excessive cost caused by schedule disruption.
Planning Time Fence: It is future master scheduling period inside which change to MPS are evaluated to prevent costly.
5
Claro Publications Private Limited Claro: Journal of Engineering Problem on Master Production Scheduling Report (With Project Available Balance and Regular/Backward Available To Promise Calculation) STANDARD FORMAT FOR MPS Week 1 2 3 4 5 6 Forecast 10 10 10 10 10 10 Order
12 5
PAB
18 13 13 3
ATP
13
Cum. ATP MPS
13 13 8
0
0
-7 17
-5
20
Discrete 8 ATP Cum. 8 ATP
20 5
8
20 0 8
8
8
LEAD TIME: 1 LOT SIZE: 20 DEMAND TIME FENCE: 2 ON HAND: 10 SAFETY STOCK: 0 PLANNING TIME FENCE: 4 Calculation: For Project Available Balance: Prior to demand time fence (DTF) 1st Period: PAB= On-hand Balance + MPS – Customer Order PAB 1=10+20-12=18 Sequencing Periods: PAB 2=Prior Period PAB+MPS-Customer Orders PAB 3=18=0-5=13 After the demand time fence (DTF) PAB= Prior Period PAB+ MPS- Greater Value of Total Customer Orders or Forecast PAB 4=13+20-20 (Orders) =13 PAB 5=13+0-10 (Forecast) =3 PAB 6= -7+0-10 (Forecast) = -7 Available to Promise (ATP) Calculations: Discrete ATP-WOL, Prior to demand time fence (DTF) 1st Period: Discrete ATP-WOL= On-hand balance + MPS- Sum of Customer Order before next MPS Discrete ATP-WOL1= 10+20-(12+5) =13 Subsequent Period: Discrete ATP- WOL= MPS- Sum of Customer Orders before Next MPS Discrete ATP-WOL3= MPS- Sum of Customer Orders before Next MPS
eeng-37-2017
Discrete ATP-WOL3=20-(20+5) =-5 Cumulative ATP-WOL: 1st Period: Cumulative ATP-WOL= On hand + MPS- Sum of Customer Order before Next MPS Cumulative ATP-WOL1= 10+20-(12+5) =13 Subsequent Periods: Cumulative ATP-WOL= Prior-Period Cumulative ATPWOL+MPS-Sum of Customer Orders before Next MPS Cumulative ATP-WOL3= 13+20-(20+5) =8 [2] Data Analysis: Vat analysis is the methodology used to describe the logical flows of raw material to finished good products. Bill of materials and parts routing are combined to reflect the logical product flows through a plant’s resources. Basic flows are classified by shape including V (Funnel), A (Pyramid) and T (Hourglass). These logical product structures providing information plant design, staffing, planning and control and information system design. Each logical product structure has control points that simplify production planning, scheduling and control. Objective: As per paper MRP and MRP II systems is need to well to understand and with one of the module and in that module need to take small problem need to define in proper manner and after defining the problem need to implement in software for a better conclusion.
III. CONCLUSION AND
DISCUSSION
For a particular given a problem MRP II system can give a better result with MRP I. It can reduce lead time and progressively it can save time for manufacturing.
Acknowledgment This is acknowledgements to NIRMA UNIVERSITY, GUJARAT, INDIA for valuable education. Thankful with appreciation for short term project for this paper.
References BIBILOGRAPHY: 1. Stephen. J. Childe, University of Plymouth, A book of introductionof Computer Aided Production Management, Chapman & Hill Publication, UK. 2.
P.B. Mahapatra, Panjab College of Engineering, A book of Computer Aided Production Management, Prentice-Hall of India publication, India.
6
Claro Publications Private Limited Claro: Journal of Engineering
Authors and Affiliations: Janakkumar R. Tanna M.Tech Mechanical-CIM, Nirma University Currently working as an Asst. Proff., K.J.Institute of Engineering & Technology, Savli, Dist: Vadodara-391770-Gujarat-India (GTU)
Ankur H.Vyas, Currently working as an Asst. Professor in K.J. Institute of Engineering and Technology, Savli , Dist: Vadodara-391770Gujarat-India (GTU)
eeng-37-2017
7
