Conversion of inputs into outputs using physical resources so as to provide the desired utility / Utilities in a form, place, possession or state or a combination to the customer while meeting the other organizational objectives of effectiveness, efficiency and adaptability.
Resource inputs into the process results into outputs from the conversion and information feed back in the operation system.
Effectiveness as a function of internal climate and workers efficiency increased with the facilities extended by management.
Advent of operations research during world war II period sow a big boost in the application of scientific techniques in the management. Various techniques such as linear programming, mathematical programming, game theory, queuing theory have become indispensable tools for management decision.
The computer era made possible the complex and repeated computations involved in various operation research and other techniques.
Service and relationship era Japan took lead in providing various services along with products for the customer satisfaction. Many production management principles have been finding their way into services in the order to improve the efficiencies and effectiveness
The procurement of raw materials, quality control and inspection of raw materials, the inventory levels of in process and finished goods, the production costs, the labour available, the machinery and equipment that is available, the warehousing capacity available.
One of the simplest approaches to scheduling is through the use of various visual aids, facilitating the planning of jobs through work centers and depicting the progress of jobs against what is planned. Charts by Henry L. Gantt
Least value at work centre/station M1 should be placed as early as possible at her left most square and if the least value occurs at the work centre M2, then place that job as the late as possible at the right most square. Now, the job column of it to be deleted and look for the left over jobs.
Suppose there is a tie, take any one.
Two machines and n jobs 10 4 2 9 3 M2 6 7 8 4 5 M1 E D C B A Time required (hours) for jobs Machines
To ensure that work flows smoothly through the process, each workstation needs to be given the same amount of time to complete its tasks on a particular unit. This is called the required Cycle Time (C) or Pace.
Cycle Time -C=Available Time Duration/Output units required in that duration.
Number of work stations (n) and Balance efficiency
Minimum number of work stations (n)=T/C
T= Sum of all task times
C= Cycle time.
Balance efficiency (Eb)= Theorotical minimum no. of work centres/ Actual no. of work centers.
A design team has identified 9 distinct tasks to be performed. After analyzing the tasks in detail, the team has also estimated the time required for each task and also the precedence relationships, as given. Suppose desired output rate is 240 units a day in an 8 hour shift.
Calculate1. Required cycle time for the desired output rate2. Minimum work centers and 3.Balance delay.
Timings and precedence 5.7 minutes Total H 0.7 I F,G 0.8 H D,E 1.5 G D 0.1 F B,C 0.3 E A 0.5 D - 0.3 C - 0.6 B - 0.9 A Immediate predecessor Required time in minutes Tasks
The ways and means of improving productivity is called work study. Work study is a management tool to achieve higher productivity in any organization, whether manufacturing tangible products or offering services to its customers. It makes use of techniques of method study and work measurement to ensure the best possible use of human and material resources in carrying out a specific activity.
To determine the best or most effective method of accomplishing a necessary operation or function. The criteria for the best method could be an increase in job satisfaction and individual morale, reduction in physiological fatigue, decrease in number of accidents and personnel injuries, minimization of material usage, tool breakage or usage of consumable supplies and increase in productivity by reduction of performance time. Every operation is or activity in an organization contains to a certain degree of mechanical, physiological, psychological and sociological factors. The purpose of work measurement is to quantify these factors.
Both time study and motion study which resulted from the integration of concepts and practices developed by F W Taylor and M. Gilberth are concerned with the systematic analysis and improvement of manually controlled work situations. However, time study is a quantitative analysis leading to establishment of a time standard whereas motion study is a qualitative analysis of a work station leading to the design or improvement of an operation/activity.
It is scientific technique of observing, recording and critically examining the present method of performing a task or job or operation with the aim of improving the present method and developing a new and cheaper method. It encompases the study of work process, working conditions and equipments and tools used to carry out the job.
Work design- is the systematic investigation of contemplated and present work systems in order to formulate, through the idle system concept, the easiest and most effective systems and methods for achieving the necessary functions/goals/purposes.
They are used giving the sequence of events occurring in the process from the beginning to the end. Some symbols are universally accepted and used.
Process charts are generally drawn for the material which goes from raw material stage to the finished goods stage. Some times may be referred to the activities performed by the worker in getting a certain process done, in such case the transport refers the movement of the man, the delay refers to his waiting involved etc. Process charts do not refer to the material and man or machine simultaneously.
Combined activities can be shown by superimposing their respective symbols so that the outer symbol represents the major activity.
3. Examine the recorded facts critically, challenging everything being done and seeking alternatives, questioning the purpose (what is achieved), the means (how is it to be achieved), sequence (when is it achieved), place (where is it achieved) and the person (who achieves it).
Method study and work measurement are two techniques of work study. Both of them are important elements in achieving higher labor productivity. Work measurement -is the application of techniques, designed to establish the time for a qualified worker, to carry out a specified job, at a defined level of performance.
Work measurement is to investigate and then eliminate ineffective time in the already improved method. Work measurement is a collection of observational and statistical procedures that are used to measure worker job performance.
Planning, procuring, preserving, handling, usage and other related aspects.
Bailey and Farmer define materials management as the management of the flow of materials into an organization to the point, where, those materials are converted into the firms end products.
Concepts of material management Raw materials Subassemblies Manufactured parts Packing materials 1.Material specifications 2.Value analysis 3. Supply market research 4. Negotiation 5. Buying 6.Quality assurance 7.Transportation Finished goods inventory Transportation Field inventory Transportation Customer Storage materials handling Production scheduling and control. Goods in process inventory Inventory decisions Procurement activities Physical distribution Materials Management
As shown above, materials management refers to the movement of production materials, from their acquisition to the stage of their consumption. Physical distribution refers to the distribution of finished goods to the customers or users. Physical distribution starts where, materials management ends.
Logistics management is a combination of both materials management and physical distribution management.
In simple form purchasing means buying an item at a price. A broader meaning is a managerial activity which includes the planning and policy activities covering a wide range of related and complementary activities. Includes the research and development strategies required for the proper selection of materials and sources from which those materials may be bought, the follow up to ensure proper delivery, the development of proper procedures, methods and forms to enable the purchasing department to carry out the established policies.
Stores or storage is the function of receiving, storing and issuing materials
It involves, supervision of incoming supplies, to ensure that they are maintained in good condition, safely and in readiness for use when required, while they are in storage and issuing them against authorized requisitions. This is not only for the purchased materials but also for partly finished goods, finished goods, spares and consumables in stores
1.Ordering costs-preparing purchase order, processing payments, receiving and inspecting the materials.
2.Carrying costs-obsolescence, deterioration, pilferage, taxes, insurance, storage, interest on the capital barrowed for inventory. Other cost like rent on building, taxes and insurances on building, depreciation on warehouse, cost of maintenance, utility charges, salaries etc.
Determination of inventory that an organization should hold is a difficult and also very significant aspect of production and operations. Too much locks capital but less than requirement may lead to stock out. Hence, it depends on trend of sales, production cycle etc.
There are two general approaches to inventory systems
What should be the size of order to place an order at the re-order point under fixed order quantity system? Bulk quantities purchase has carry costs and small quantities reduce holding cost but add order cost. Economic order quantity or optimal order quantity is the technique is the order size at which total cost, comprising ordering cost plus carrying cost is the least.
EOQ can be calculated with the following assumptions
1.Demand is constant during the period.
2.Lead time is constant i.e. time from ordering to receipt.
3.Price per unit is also constant.
4.Inventory holding cost is based on average inventory.
Total const (TC)=Annual demand X Purchase const/unit + Annual demand / Quantity to be ordered X Cost of placing an order + Quantity to be ordered / 2 X Holding cost per unit of average inventory per annum.
TC = DC + D/Q X S + Q/2 X H
DS/Q = Annual ordering cost.
(Q/2)H = Annual holding cost.
The cost of ordering is equal to the cost of carrying