Friday, December 30, 2011

Competencies of Industrial Engineer

Previously we already mentioned about competencies of Industrial Engineer. Here we going to share a bit more about the competencies.


 1. Work Design and Measurement

 Job design: assigning various components i.e. tasks to a job to be performed by a worker in daily routine. Job design involves specifying the content and methods of job that what, who, how, where the job will be done.

Job Design must be:
• Performed by experienced personnel with good knowledge and proper training
• Compatible to goals of the organization
• written form
• Consensus of management and employees


this is the explanation of the map above:
a. Method analysis: Methods analysis is a technique in job design in which the job is usually broken down into various steps or procedures. The workplace arrangement, tools and equipment used, materials used, and the worker’s skill set required for the performance of the job are all studied in detail in order to devise better methods of performing a job.
   I. Flow Process: Flow process chart shows the flow of materials, labor, and products (semi-finished and finished) from one place to the other in the facility. It helps in identifying the various sources of delay in the process, which may be eliminated in order to achieve better efficiency.
   II. Employee-machine activity: Employee-machine activity charts help in methods analysis of jobs for improving the efficiency of the employees and the machines. In employee-machine activity chart, we show the various time instants and the activities of the employee and the machine simultaneously.




b. Behavioral aspect of Job Design
      I. Job enlargement: Job enlargement is the horizontal loading of the job of a worker. This means certain tasks of the same skill and mental level as being handled by the worker earlier are added to the job.
   II. Job Rotation: Job rotation, highly repetitive tasks like in assembly lines are swapped (interchanged) amongst workers after a suitable duration of time.
      III. Job enrichment: Job enrichment means giving some additional responsibilities to the worker, which are slightly more dignified than the routine tasks being handled by him. This is also called vertical loading of the job.


c. Principles of motion economy: Principles of motion economy aim at minimizing the human fatigue of workers due to repetitive motion of the different parts of the body like hands, feet, eyes, etc. and, thus, maximizing the efficiency of the worker during the performance of a job.


Work Measurement: Work measurement is the application of techniques designed to establish the time for qualified worker to carry out a specified job at a defined level of performance.  
  a. Stopwatch time: Stopwatch time study is a method of work measurement used for measuring the standard time duration of repetitive tasks. Standard time: Standard time duration means the time taken by an average worker to perform a task at a sustainable rate under the given facility arrangements.
   b. Work Sampling: Work sampling is a method used to determine the fraction of idle time of machines or workers during the day or to determine the time spent by workers on different types of tasks. This method is suitable for jobs which are non-repetitive in nature. 


 2. Plant Location and Layout

Plant layout is often a compromise on a number of factors including:

* Need to keep the distance to the transfer of materials between plant / warehouse units to minimize cost and risk reduction.
* Geographical limitations of the site;
* Interaction with existing or planned facilities, such as existing roads, sewers and utility lines;
* Cooperation with other plants in the field;
* Need plant and utility maintenance;
* Need to hazardous materials resources on site boundaries and the local population lives in the neighborhood to install;
* The need for the prison where leakage of flammable materials may occur to prevent
* The need for access to emergency services;
* The need to escape on-site staffing;
* The need for acceptable working conditions for operators.

The most important factor in changing the plant layout, as long as opinions are concerned about the safety,

* Prevention, reduction and / or easing the tensions related events (Domino);
* Provide a safe place in occupied buildings;
* Controlling access by unauthorized persons;
* Improving access to emergency services.

Defining plant layout designers must take into account the factors described in the following paragraphs.
Built-in safety

The main principle is to eliminate the inherent danger to safety together. The best way to achieve this is to reduce the inventory of hazardous substances so that no more serious threat is presented. But it is not often easily accessible and by definition not a COMAH facility did not do this. Other possible methods are intrinsically safe design:

* Reduction of the activation of reserves;
* Substitution of hazardous substances with less hazardous alternatives
* Relax in an attempt to adverse conditions, temperature, pressure reduction;
* A simple systems / processes to the potential loss of content or restrict any errors cause dangerous event;
* Fail-safe construction as positioner failure.

Plant layout considerations relating to the achievement of security first and foremost for those who are concerned about the domino effect (see below).
Dow / Mond indices

These are useful indicators of the risk assessment of processes or software, they are senior to the existing facilities and the assignment of incident classifications. They provide the comparative size of a fire and explosion process are useful tools for plant layout development, because they objective distance distances to be considered at all stages.

Method for making a quick method for ranking, based on the Dow / Mond index detailed ILO PIACT greater practical risk management handbook, 1988.

Although this useful rule of thumb methods for primary plant layouts change, they do not replace the risk assessment from the distance between power devices use these systems are based on technical evaluations, and to some extent the experience rather than a detailed analysis.
Domino effect

Risk assessment of the site layout is very important for controlling the effects of loss and opportunities to ensure sastkatsats minimized. Domino is a fire, explosion (shock wave and missiles), or toxic gases causing loss of control government actions in a different location.
Four

A fire in four ways.

* Direct ignition, such as running liquid fires);
* Convention;
* Radiation;
* Conduct.

Spread of fire in other parts of its territory, the origin be prevented by vertical and horizontal sections using fire walls and floor. More information can be found in BS 5908 '1990 [8]. Taking into account the need to spread through the flammable substances list, piping and ventilation systems. Delayed ignition of the release could lead to the spread of fire through such systems the combustible gas to disperse vapors.

Protection against Domino effects by convention, heat conduction and radiation can achieve enhanced security principles, namely to ensure that the distance between the plant elements are sufficient to heat related plants compromising the safety of the plant. If it is not possible because of other constraints, other methods such as fire walls, active or passive fire protection are considered.
Explosion

Extension of an explosion may directly or indirectly from pressure waves of missiles. If fires are inherently safe methods to be considered:

* Organize distances, so that damage to adjacent plants was not even in the worst case;
* Display obstacles blast walls, placement of a strong building;
* Protection of plants against damage, for example, the thicker walls of vessels;
* Management Explosion relief vents away from sensitive areas such as other plants or buildings, roads around the place outside.

But the latter can no practical solutions, in particular missile, and risk analysis may be required to provide adequate security to show.
Toxic Gas Releases

Toxic gas released, a domino effect of related plants cause in making useless and injuring operators. Prevention / mitigation of such effects may affect the supply of automated systems using the principles of inherently safe and comfortable control room (see below occupied buildings).
Here's other example of Plant Layout
 source: http://aaatd.com/PlantLayout.htm

 3. Engineering Economy

 

Engineering economics, previously known as engineering economy, is a subset of economics for application to engineering projects. Engineers seek solutions to problems, and the economic viability of each potential solution is normally considered along with the technical aspects.
In the U.S. undergraduate engineering curricula, engineering economics is often a required course.[citation needed] It is a topic on the Fundamentals of Engineering examination, and questions might also be asked on the Principles and Practice of Engineering examination; both are part of the Professional Engineering registration process.
Considering the time value of money is central to most engineering economic analyses. Cash flows are discounted using an interest rate, i, except in the most basic economic studies.
For each problem, there are usually many possible alternatives. One option that must be considered in each analysis, and is often the choice, is the do nothing alternative. The opportunity cost of making one choice over another must also be considered. There are also noneconomic factors to be considered, like color, style, public image, etc.; such factors are termed attributes.[1]
Costs as well as revenues are considered, for each alternative, for an analysis period that is either a fixed number of years or the estimated life of the project. The salvage value is often forgotten, but is important, and is either the net cost or revenue for decommissioning the project.
Some other topics that may be addressed in engineering economics are inflation, uncertainty, replacements, depreciation, resource depletion, taxes, tax credits, accounting, cost estimations, or capital financing. All these topics are primary skills and knowledge areas in the field of cost engineering.
Since engineering is an important part of the manufacturing sector of the economy, engineering industrial economics is an important part of industrial or business economics. Major topics in engineering industrial economics are:
  a. the economics of the management, operation, and growth and profitability of engineering firms;
    b. macro-level engineering economic trends and issues;
    c. engineering product markets and demand influences; and
the development, marketing, and financing of new engineering technologies and products

4. Production Planning and Inventory Control

     Production planning is the function of establishing an overall level of output, called the production plan. The process also includes any other activities needed to satisfy current planned levels of sales, while meeting the firm's general objectives regarding profit, productivity, lead times, and customer satisfaction, as expressed in the overall business plan. The managerial objective of production planning is to develop an integrated game plan where the operations portion is the production plan. This production plan, then, should link the firm's strategic goals to operations (the production function) as well as coordinating operations with sales objectives, resource availability, and financial budgets.
    The production-planning process requires the comparison of sales requirements and production capabilities and the inclusion of budgets, pro forma financial statements, and supporting plans for materials and workforce requirements, as well as the production plan itself. A primary purpose of the production plan is to establish production rates that will achieve management's objective of satisfying customer demand. Demand satisfaction could be accomplished through the maintaining, raising, or lowering of inventories or backlogs, while keeping the workforce relatively stable. If the firm has implemented a just-in-time philosophy, the firm would utilize a chase strategy, which would mean satisfying customer demand while keeping inventories at a minimum level.
    The term production planning is really too limiting since the intent is not to purely produce a plan for the operations function. Because the plan affects many firm functions, it is normally prepared with information from marketing and coordinated with the functions of manufacturing, engineering, finance, materials, and so on. Another term, sales and operations planning, has recently come into use, more accurately representing the concern with coordinating several critical activities within the firm.
    Production planning establishes the basic objectives for work in each of the major functions. It should be based on the best tradeoffs for the firm as a whole, weighing sales and marketing objectives, manufacturing's cost, scheduling and inventory objectives, and the firm's financial objectives. All these must be integrated with the strategic view of where the company wants to go.
    The production-planning process typically begins with an updated sales forecast covering the next 6 to 18 months. Any desired increase or decrease in inventory or backlog levels can be added or subtracted, resulting in the production plan. However, the production plan is not a forecast of demand. It is planned production, stated on an aggregate basis. An effective production-planning process will typically utilize explicit time fences for when the aggregate plan can be changed (increased or decreased). Also, there may be constraints on the degree of change (amount of increase or decrease).
    The production plan also provides direct communication and consistent dialogue between the operations function and upper management, as well as between operations and the firm's other functions. As such, the production plan must necessarily be stated in terms that are meaningful to all within the firm, not just the operations executive. Some firms state the production plan as the dollar value of total input (monthly, quarterly, etc.). Other firms may break the total output down by individual factories or major product lines. Still other firms state the plan in terms of total units for each product line. The key here is that the plan be stated in some homogeneous unit, commonly understood by all, that is also consistent with that used in other plans.

Inventory control
The basic function of stock (inventory) is to insulate the production process from changes in the environment as shown below.
Note here that although we refer in this note to manufacturing, other industries also have stock e.g. the stock of money in a bank available to be distributed to customers, the stock of policemen in an area, etc).
One point to note from the above diagram is that most of the activities are a cost - it is only at the final point (sales of finished goods) that we get revenue to set against our costs and hopefully make a profit (= revenue - cost). Hence if we have cost associated with stock we need to deal with that stock in an Effective, Efficient and Economic manner (the 3E's as I tend to term it).
The question then arises: how much stock should we have? It is this simple question that inventory control theory attempts to answer.
There are two extreme answers to this question:
a lot
-this ensures that we never run out                                                                                                     
-is an easy way of managing stock
-is expensive in stock costs, cheap in management costs
none/very little
-this is known (effectively) as Just-in-Time (JIT)
-is a difficult way of managing stock
-is cheap in stock costs, expensive in management costs

We shall consider the problem of ordering raw material stock but the same basic theory can be applied to the problem of:
-deciding the finished goods stock; and 
-deciding the size of a batch in a batch production process. 

The costs that we need to consider so that we can decide the amount of stock to have can be divided into stock holding costs and stock ordering (and receiving) costs as below. Note here that, conventionally, management costs are ignored here. Holding costs - associated with keeping stock over time
-storage costs
-rent/depreciation
-labour
-overheads (e.g. heating, lighting, security)
-money tied up (loss of interest, opportunity cost)
-obsolescence costs (if left with stock at end of product life)
-stock deterioration (lose money if product deteriorates whilst held)
-theft/insurance
Ordering costs - associated with ordering and receiving an order
-clerical/labour costs of processing orders
-inspection and return of poor quality products
-transport costs
-handling costs 
Note here that a stockout occurs when we have insufficient stock to supply customers. Usually stockouts occur in the order lead time, the time between placing an order and the arrival of that order.
Given a stockout the order may be lost completely or the customer may choose to backorder, i.e. to be prepared to wait until we have sufficient stock to supply their order.

Note here that whilst conceptually we can see that these cost elements are relevant it can often be difficult to arrive at an appropriate numeric figure (e.g. if the stock is stored in a building used for many other purposes, how then shall we decide an appropriate allocation of heating/lighting/security costs).

5. Statistical Quality Control

to understand more about SQC let's watch this video:


source: Youtube

6. Linear Programming

   Linear programming is mathematical approach to the problem of allocating limited resources among competing activities in an optimal manner. Specifically, it is a technique used to maximize revenue, contribution margin (cm) , or profit function or to minimize a cost function, subject to constraints.
     Linear programming consists of two important ingredients: (1) objective function and (2) constraints, both of which are linear. In formulating the LP problem, the first step is to define the decision variables that one is trying to solve. The next step is to formulate the objective function and constraints in terms of these decision variables.
    For example, assume a firm produces two products, A and B. Both products require time in two processing departments, assembly and finishing. Data on the two products are as follows:
Linear Programming (LP)
     The firm wants to find the most profitable mix of these products                                                   
     First, define the decision variables as follows: A = the number of units of product A to be produced B = the number of units of product B to be produced Then, express the objective function, which is to maximize total contribution margin (TCM), as: TCM = $25 A + $40 B Formulate the constraints as inequalities: 2 A + 4 B < 100 3 A + 2 B < 90 and do not forget to add the non-negative constraints: A > 0, B > 0                                                                                           
Posted by at

1 comment:

Subscribe to: Post Comments (Atom)