FACILITY LAYOUT & LOCATION PROF. DR. ORHAN TORKUL M. RAŞİT CESUR

Time Study OBJECTIVES; Understand the concepts of time study and time standards Understand the importance of time standards in facilities planning Be able to identify various techniques for establishing time standards Be able to identify the steps for performing a stopwatch time study Understand the difference between observed, normal, and standard times and be able to calculate each Understand the concepts of normalizing and allowances

What is a Time Standart A time standard is defined as “the time required to produce a product at a workstation with the following three conditions; a qualified, well-trained operator working at a normal pace doing a specific task. Experience is usually what makes a qualified, well-trained operator, and time on the job is the best indication of experience. Normal pace is the pace at which a trained operator, under normal conditions, performs a task with a normal level of effort.

The time standard is used to… Determine the number of machine tools to buy. Determine the number of production people to employ. Determine manufacturing costs and selling prices. Schedule the machines, operations, and people to do the job and to deliver on time with smaller inventories. Determine the assembly line balance and the conveyor belt speed, load the work cells with the correct amount of work, and balance the work cells.

The time standard is used to… Determine individual worker performance and identify and correct problematic operations. Pay incentive wages for outstanding team or individual performance. Evaluate cost reduction ideas and pick the most economical method based on cost analysis, not on opinion. Evaluate new equipment purchases to justify their expense. Develop operation personnel budgets to measure management performance.

How Many Machines Do We Need? The answer depends on two pieces of information: How many pieces do we need to manufacture per shift? How much time does it take to make one part? (This is the time standard.) Number of Machines = Example; The marketing department wants you to make 2,000 wagons per 8-hour shift. It takes minute to form the wagon body on a press. Assume 50 minutes downtime per shift (breaks, cleanup, etc.) and 75% utilization of work. Time Standart Plant Rate

How Many Machines Do We Need? Production Time= (8x60 – 50) x 0.75 = R = = Number of Machines = = 2.48 ≈ 3 machines Machine numbers should be rounded to upper value

How Many People Should We Hire? Number of labor = Example; The is the hours required to produce 1,000 pieces of water valve. The marketing department has forecasted sales of 2,500 water valves per day. Assume 75% performance. How many people are needed to make water valves? Total Time Required for Production Shift Duration

Process Diagram of Water Valve

Solution of Example ≈ 185,25 hr per 1000 units For 2500 units 185,25*2,5= 463,125 hr = 463,125 = 58 labours are needed. 138,94 hr per 1000 units 0,75 138,94 hr per 1000 units 0,75 463,125 hr 8 hr per day

Plant Layout 4 basic types of plant layout; Process Layout Product Layout Group (Cell) Layout Fixed Layout

Process Layout Used when the operations system must handle a wide variety of products in relatively small volumes (i.e., flexibility is necessary) Designed to facilitate processing items or providing services that present a variety of processing requirements. The layouts include departments or other functional groupings in which similar kinds of activities are performed. A manufacturing example of a process layout is the machine shop, which has separate departments for milling, grinding, drilling, and so on.

Process Layout

Prduct Layout Product layouts are used to achieve a smooth and rapid flow of large volumes of products or customers through a system. A job is divided into a series of standardized tasks, permitting specialization of both labor and equipment. The large volumes handled by these systems usually make it economical to invest huge amount of money in equipment and job design.

Prduct Layout Operations are arranged in the sequence required to make the product. For instance, if a portion of a manufacturing operation required the sequence of cutting, polishing, and painting, the appropriate pieces of equipment would be arranged in that sequence. Product layouts achieve a high degree of labor and equipment utilization.

Prduct Layout Material LMCG MLPL ACGD Product

Group (Cell) Layout Cellular manufacturing is a type of layout in which machines are grouped into what is referred to as a cell. Groupings are determined by the operations needed to perform work for a set of similar items, or part families that require similar processing. Cellular layout provides faster processing time, less material handling, less work-in-process inventory, and reduced setup time. Used when the operations system must handle a moderate variety of products in moderate volumes

Group (Cell) Layout Cell 3 LM G G Cell 1 Cell 2 Assembly Zone A A L M D L L M Shipment D Warehouse G

Fixed Position Layout In fixed-position layouts, the materials or major components remain in a fixed position, and workers, materials, and equipment are moved as needed. Fixed-position layout is used when product is very bulky, heavy or fragile Fixed-position layouts are used in large construction projects (buildings, power plants, and dams), shipbuilding, and production of large aircraft and space mission rockets. Fixed-position layouts are widely used for farming, firefighting, road building, home building, remodeling and repair.

Fixed Position Layout M Product Warehouse D P L

Cost of Product Cost of product is consisted of; Fixed costs (labour cost, management cost, amortization etc…) Variable cost (operation cost, material cost etc…) Auxiliary services cost Material handling cost To compare cost of product for every layout; Variable cost is same for same products. Fixed cost, material handling cost ant cost of auxiliary services are needed.

Cost of Product C F :Fixed cost (yearly), C V :Variable cost (yearly) C H : Material handling cost (yearly) C A : Cost of auxiliary services (yearly), C P : Production cost i: Interest, n: number of years considered, n A : the period of amortization Cost of product for every layout can be compared as calculatin present worth of production cost; C P = C F (P/A;i;n) + C V (P/A;i;n) + C H (P/A;i;n) + C A (P/A;i; n A )

Cost of Product To calculate unit cost total number of products produced during the production period is needed. Total number of products (N P ) = R (plant rate) * total production time in the period Unit cost (C U ) = When production cost of different layouts are calculated and compared pairly, the interest ratio (i) making them equal (C P1 = C P2 ) is the internal rate of return. CPCP NPNP

Cost of Product Break – even point is for finding out the time when it is started to gain. Internal rate of return is for finding out the intereset ratio makes the production profitable. Present worth is for finding out the present value of production cost.

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