The historical evolution of IT in production scheduling and manufacturing
The evolution began in the 1770s in Europe and in the 1800s in America. Prior to that time manufacturing was simple and being performed by craftsmen and apprentices. In the 1800s century.it started to flourish and changed into the technical term production, whereby more, machines were being used in process of manufacturing.
The traditional outlook of manufacturing undergo changes when Adam smith advocate the economic benefits of specialization of labour in manufacturing sectors. He recommended the breaking down of jobs into subtasks and promoted skilled and efficiency in workers.in the 1800s century, F.W Taylor implemented Smith’s theories and developed scientific management.
F.W Taylor and planning office
In general, F.W Taylor is acknowledged for his fundamental contributions to scientific management in the late 1800s, Frederick.W Taylor’s most imperative contribution to production scheduling was his creation of the Planning office (described in Taylor, 1911). His separation of planning from execution justified the use of formal scheduling methods, which turn out to be critical as manufacturing organizations grew in difficulty. It established the view that production scheduling is a distinctive decision making process in which individuals share information, make plans, and respond to unexpected events. The key element of planning office was the bulletin board. There was mainly two of them: one for planning office and another for shop floor according to Thompson, 1974. There was enough space available for each workstation. The bulletin board displayed each workstation, the tasks and operation performed, orders currently being performed and future orders that would eventually need to proceed. In modern software, this bulletin board was replaced by the dispatch lists that show all of the work waiting for processing at a workstation.
In line with Mitchell 1939. Countless firms implemented versions of Taylor’s production planning office, elaborated on the role of the production planning department, comprising of routing, dispatching and scheduling.
The widespread acceptance of Taylor’s approach reflects the prominence of the organizational standpoint of scheduling, a system-level outlook that scheduling is part of the complex flow of information and decision-making that forms the manufacturing planning and control system (MPC) (McKay et al., 1995; Herrmann, 2004). The upswing of information technology did not disregard the planning functions defined by Taylor; it simply automated them using increasingly complex software that is typically divided into modules that perform the different functions more quickly and accurately than Taylor’s approach.
2.0 Introduction
An operation is that part of a business organization that is accountable for producing goods and services. Goods are defined as the physical items that include raw materials, parts, and subassemblies for example, a printer that connects to a computer, and the final product can be automobile, electronic products such as cellphones, laptops and other devices. Services are distinct from goods as they possess different characteristic such as intangibility, furthermore, services are activities that offer some combination of time, location, form, or psychological value.
Definition of goods
In the 1800s century, in line with Adam Smith (1776) & Demsetz (1993), said that goods have exchangeable value and so a characteristic of a good is that it’s as ownership rights which can be established and exchanged. Goods can be measured as embodying specialized knowledge in a way that is highly advantageous for promoting the division of labour.
While according to Nassau Senior (1863) he defined goods as material things, meaning that goods are tangible and comprise physical dimensions.
Characteristics of goods
The physical attributes are preserved over long period of time.
Goods possess ownership rights
Goods exist independently of their owner
They are exchangeable
Unit ownership rights can be exchanged between institutions
Definition of services
Even though, we have found proper definition of goods and their characteristics. The definition of services has never reached consensus. It is difficult to obtain a full acceptance of a definition of services. As it has been searched on different perspectives, according to Fisk et al.1983 they defined services as a form of separate part of a company marketing strategy (Lovelock 1983)
Characteristics of services
Intangible: intangible things are not physical objects and only exist in relation to other things. Examples include a brands image, or goodwill.
Heterogeneity: refers to the multifaceted different experience that may be had from a single type of service is considered as a factor to distinguish goods from services. It is also considered as a common service which varies to the context, nature and requirement of each customer. It varies according to diverse quality standards related with costs; services also vary across cultural background and regions.
Inseparable Services is possibly said to be inextricably linked with customers in terms of production and consumption for this reason it is said that service is inseparable. However, this characteristic is open to challenge and interpretation.
Perishability: Adam Smith (1776) defines a service as being perishable in the very instance of its performance and leaves no trace or value behind it.
Definition of psychological value
Psychological value is related to continuous improvement of a job. It is the desire and ability of a business to develop and incorporate ways to improve itself through creativity, new products, ideas, technology, and new methods and with the enthusiasm of customer and a positive emotional response on individual and social levels.
An example of goods and services are present everywhere it may be in the form of travelling, internet connection, and shopping. The operation function of businesses can be accessed from a broader perspective. The combined success and failure of company’s operation functions has an impact on the aptitude of an economy to compete successfully.
The ultimate situation for a business organization is to match supply and demand. Having excess supply of excess capacity is wasteful and costly to an organization. Having too little opportunities means possible customer dissatisfaction. The key functions on the supply side are operations and supply chains, and sales and marketing on the demand side.
The operation has as functions to produce goods and deliver services; it is also dependent on the support and input from other areas of the organization. Businesses have mainly three areas of interest as depicted in figure 1.1: finance, marketing and operation. Most organization has the same pattern whether it is a retail store, or a manufacturing firm, businesses follow the same basic functions.
Three basic functions of business organizations
The finance department is accountable for securing financial resources at good prices and allocating those resources all over the organization. Business also takes into consideration budgeting, analyzing investment proposal and providing resources for operations.
Operations and supply chains are fundamentally linked and no organization could exist without both. A supply chain is defined as the sequence of an organization.
Marketing section is responsible for the assessment of consumer’s needs and wants, selling and promotion strategies. The operation department is in charge to produce goods and services on time. An operation refers to the core of what an organization does. Operation management is defined as the proper management of systems or processes that create goods or produce services.
Figure 1.1 Three basic functions of business organizations
Definition of Supply chain management
Supply chain management is the practice of manufacturing and distributing physical goods as efficiently as possible. Supply chain management encompasses the entire process of manufacturing and distributing physical goods, from supplier’s supplier to customer’s customer. Business functions that are within the realm of supply chain management include: forecasting and planning, procurement and purchasing, manufacturing and assembly, warehousing and distribution, shipping and transportation, returns and refurbishment, inventory management and order management. Or, stated more simply, supply chain management includes the functions: plan, buy, make, store, move, sell and return. (CII Institute of Logistics, Chennai) as shown in figure 1.2
Characteristics of supply chain
The supply chain is evenly internal and external to an organization. The internal part of a supply chain is related to the operations functions whereas the external part provide raw materials, parts, equipments and other inputs needed to carry out production. The conception of goods and services involves transforming inputs into outputs. Examples of inputs are: capital, labour, and information needed to produce the good or services by making use of more than one transformation process (such as storing. transporting and repairing).in order to ensure that output is produced on time, the organization takes measures at various levels of operations. There is a comparison between expected and actual standards so that there is corrective action taken.
A simple product supply chain diagram
Figure 1.2: A simple product supply chain
Operational model
Transformation process:
‘ Product design
‘ Process planning
‘ Production control
‘ Maintenance
Figure 1.3 the operations function involves the conversion of input into output
The core of the operation function is to add value during the transformation process: value added is the word used to depict the difference between the cost of inputs and the value of or price of output.
The scope of operations management
The management of an operation department are involved in multiple activities to produce goods and services such as process design, selection of technology, planning so that it can help improve the quality standards of a particular business. There are also interrelated activities associated with the process and they are; capacity improvement, scheduling managing inventories and assuring quality and more.
Operation management linked with different supporting functions
Operation management interacts with other functional areas in an organization including the legal aspect of businesses, the managing information systems, the accounting department, Human Resource Management and Public Relations as depicted in the following diagram.
Legal aspect
The legal aspect must be consulted with the employees, customers, suppliers and transporters as well as the liability and environment issues.
Accounting
The accounting department helps to supply information to management on the different aspects for example: costs of labour, cost of raw materials and overheads.
Managing information systems (MIS)
The MIS helps management to effectively take decisions and this mainly occurs through designing system to capture and store relevant information and data reports.MIS is an effective tool to control and aid decision making process in operation management.
Human resources
The human resources department is concerned with recruitment and training of personnel, labour relations, contract negotiations, wage and salary administration, assisting in manpower projections and ensuring health and safety of employees.
Public relations
Public relations have responsibility for building and maintaining a positive public image of the organization. Public relations provide many potential benefits. An obvious one is in the marketplace. Other potential benefits include public awareness of the organizations as a good place to work.
Figure 1.4 operation linked with multiple functions
Operation management and decision making
The main role of operation manager is to plan and to decide for the best interest of a company. In order to be able to achieve these goals, the manager has to exert considerable influence over the degree to which the objectives are meant. Most decisions have many possible alternatives that can impact differently on costs or profits. As a result, it is important to make informed decisions.
Operation management experts make a number of key decisions that influence the entire organization. They take into concern the following:
What resources will be needed and in what quantity?
When will each resource be needed? When should the work be scheduled?
When should materials and other supplies be ordered?
When corrective actions are needed?
Where will the work be completed?
How will the design of the product be?
Who will be responsible to carry out the work?
There are a broad range of decisions that operation managers have to decide and various tools are essential for the proper handling those decisions. There are many approaches being used in order to help decision making. This part will be discuss in further details in the below general approaches.
Models
A model is defined as an attraction of reality, a simplified representation of something. For example a child’s toy laptop is a model of a real electronic device. It possesses many of the same features (for example, shape relative proportions, screen) that make it appropriate for the child learning, but it does not have the same properties such as real hardware.
Classification of models
Physical model
A physical model is similar to real life counterparts. For Example, airplanes, child’s toy car, train and scale model buildings. The benefit of such model is that it has a visual correspondence to reality.
Schematic models
These types of models are more abstract than their physical counterpart, which means that they have fewer similarities compared to the real models. Examples of schematic models are graphs and charts. The advantage of using this model is that it is relatively simple to construct and change. There is clearer visual correspondence and more flexibility.
Mathematical models
They are abstract and is completely different from real perspective. Examples are numbers, symbols and formulas. This type of model is the simplest one to manipulate and it is an essential element for inputs for computers and calculations.
Benefits of using models
Models play an important role in decision making in the operation and production of goods and services. They aid to simplify tasks and they are heavily integrated into the material process. For each model, it is an essential step to learn about it, its purpose, how it is used to generate results and how the results are interpreted and used. Model are an important tools for manager as it is generally less expensive way than dealing with the real situation. It helps to increase understanding of the problem and enable managers to analyze the problem in depth. It serves as a consistent tool for evaluation and provide standardize format to analyze problems. Manager may also make excessive use quantitative information over qualitative one.
Production Management
Production management involves the planning, organizing and controlling of the whole production process. The interrelation of these behavior and operations concerned in the production of goods and the services is known as production system. (Evans, 1993)
The objective of this study is to explain the principles behind current production philosophies in particular Productivity, Material Requirement Planning (MRP), time study just in time (JIT) and optimized production technology (OPT).These techniques aim to improve the production system in distinct area, each placing an emphasis upon different components.
Definition of productivity
‘Productivity is the optimized utilization of all available resources, investigation into the best known resources and generating new resources, through creative thinking, research and development and by the use of all possible improvement techniques, methods and approaches for the production and distribution of quality goods and services'( Ramsay,1973)
Productivity Concepts and Measures
In general productivity measures the aptitude to produce a good or service. Specifically productivity is a way to measure specified resources and how they are managed to achieve timely objectives in terms of quantity and quality. The term productivity may also be distinct as an index that measures output (good and services) relative to the input (labor, material, energy used to produce the output).productivity can be expressed as;
‘ Productivity = (System Output / System Input )
Production System
The production system produces products of an organization where resources flowing in a definite system, are collective and altered in a controlled manner to add value in accordance to policies communicated by the management.
Characteristics of Production System
The production system has the following characteristics:
1. Production is an organized activity, so every production system has an objective.
2. The system transforms the various inputs to useful outputs.
3. It does not operate in isolation from the other organization system.
4. There exists a feedback about the activities, which is essential to control and improve system performance.
Classification of Production System
Production systems can be classified as Job Shop, Batch, Mass and Continuous Production systems.
outpuou
1.5 Figure classification of production system
Job Shop Production
Job shop production is characterized by building up one or few quantity of a product. It is designed and produced as per the requirement of customers within prefixed time and cost. Job shop production has feature of low volume and high variety of products and consist of all-purpose machines set into diverse departments. The production of such job demands exceptional technologies, and the demand is being processed on machines in a positive sequence.
Characteristics of Job Shop Production
The Job-shop production structure is followed while there is:
1. High multiplicity of goods and low volume.
2. Make use of general purpose machines and amenities.
3. Very skilled operators who can engage in each job as a challenge because of exclusivity
4. Immense inventory of resources, tools, parts.
5. Thorough planning is indispensable for sequencing the supplies of each product, capacities for each work centre and order priorities.
Batch Production
The American Production and Inventory Control Society (APICS) ‘define batch production as a form of manufacturing in which the job passes from beginning to end the functional departments in lots or batches and every lot may have a special routing.’ It is characterized by the production of restricted number of products shaped at regular intervals and stocked awaiting sales.
Characteristics of Batch Production
Batch production system is used in the following conditions
1. While there is shorter production runs.
2. Plant and machinery are flexible.
3. When the set up of plant and machinery is used for the production of part in a batch and modify the set up is necessary for processing the subsequent batch.
4. Manufacturing lead time and cost are lower for the reason that it is compared to job order production.
Mass Production
Mass production makes use of separate parts or assemblies by means of a continuous flow to manufacture products. This production method is justified by large volume of production. The product layout are aligned and the process is standardized specifically all output follow the same pattern.
Characteristics of Mass Production
Mass production is used in the next conditions:
1. There is Standardisation of product and process cycle.
2. Special purpose machines are used having advanced production capacities and output rates.
3. There is large volume of products.
4. Mass production also has shorter cycle time of production.
5. Lower processing rates of inventory
6. The presence of completely balanced production lines.
7. There is an unbroken link among Flow of materials, components and parts without any back tracking.
8. The Production planning and control is simple
9. Lastly there is total automatic Material handling
Continuous Production
The production services are arranged as indicated by the sequence of production operations from the start of production to the final product. The good and services are inclusive when they passed through the sequence of operations all the way through material handling devices for example conveyors and transfer devices.
Characteristics of Continuous Production
Continuous production is used in the following circumstances:
1. Enthusiastic plant and equipment by means of zero flexibility.
2. Where there is fully automated Material handling
3. The Process follows a predetermined sequence of operations.
4. In continuous production Component materials cannot be acknowledged with finishing product.
5. The Planning and scheduling is a regular completion
Manufacturing Planning and Control from a Scheduling Perspective
Production scheduling forms part of the manufacturing planning and control (MPC) which comprise of the activities performed in companies to plan and control its production efficiently. The process starts from the initial demand management to execution of work on the shop floor. This chapter gives an indication on the role of scheduling in MPC and how that role has evolved and become more and more complex.
Purpose of manufacturing planning and control (MPC)
The purpose of MPC is to agree on what to produce in a company and manufacture good/services as effectively as possible. The MPC activities must always be performed in an approach that satisfies the overall objectives of a company. in general to maximize profits and minimize cost, while at the same time making sure the production can be controlled in a practical way.
MPC also takes into consideration strategic plan at a high level through planning and scheduling activities. Diverse questions have to be answered which ultimately results in a detailed schedule that can be executed by the company’s production resources. The most popular used method is Material Requirement Planning (MRP).
Historically, planning and scheduling has been carried out manually but since computers became accessible for more widespread use. MPC has been computerized and the evolution of MPC has very much followed the evolution of information technologies. To further elaborate on production scheduling in context, MRP is described in section’
Material Requirement Planning
Material requirement planning (MRP) is a material planning process with the purpose of making use of a production bill-of material and a master production schedule to agree on material needs and replacement timing. (Moon & Phatak 2005,Aghazadeh 2003)
Material resource planning (MRP II)
Material resource planning (MRPII) is typically said to be a improvement of MRP, where the advancement lies in the ability to incorporate other resources than the materials (Mattson, 2004).
The Difference between Planning and Scheduling
The difference between planning and scheduling is a somewhat indistinct part and the definition to some degree varies between different sources in the literature. The broad idea is that planning is made at a higher, aggregated level over longer periods and that scheduling involves more details and is completed over shorter time period. Since the MPC activities proceed from planning to schedule each step adds further details and brings the initial demands closer to being executed on the shop floor. Planning uses expected demands and forecasts and as a result always contains some level of uncertainty. As the plans evolve through the planning and scheduling process and details are added, that uncertainty is gradually removed.
Advanced Production Scheduling
The APICS defines APS as a system supporting decision at all planning levels or only at operational planning levels. To value the concept of APC .it comprise of several functionalities more precisely to the concept of the research the system is defined as any computer program that uses advanced mathematical algorithms or logic to perform optimization and simulation on finite capacity scheduling, sourcing, capital planning, resource planning ,forecasting, demand management and others.
Information System
Information system (IS) is defined by Stefansson,1999 as a system that make use of information technology to capture, transmit, store, retrieve, manipulate, and display information. Information system is categorized by application, for example, manufacturing systems, planning systems and production scheduling systems. An additional way of making use of Information system is online systems, decision based systems and knowledge based systems.
Information Technology (IT)
Information technology (IT) is the hardware and software with the principle of making information system possible.
Hardware is defines as the devices and other tangible equipment involves in the processing information, for example computers workstations, physical networks and transmitting devices.
Software is the computer program that interprets the user inputs and tells the hardware what to do (Stefansson, 1999)