• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Tn6 facility+layout
 

Tn6 facility+layout

on

  • 714 views

 

Statistics

Views

Total Views
714
Views on SlideShare
714
Embed Views
0

Actions

Likes
0
Downloads
42
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Tn6 facility+layout Tn6 facility+layout Presentation Transcript

    • 1 Facility Layout
    • 2 OBJECTIVES • Facility Layout and Basic Formats • Process Layout • Layout Planning • Assembly Line balancing • Service Layout
    • 3 Facility Layout Defined Facility layout can be defined as the process by which the placement of departments, workgroups within departments, workstations, machines, and stockholding points within a facility are determined This process requires the following inputs: • Specification of objectives of the system in terms of output and flexibility • • Estimation of product or service demand on the system • • Space requirements for the elements in the layout Processing requirements in terms of number of operations and amount of flow between departments and work centers Space availability within the facility itself
    • 4 Criteria for a good Layout – designing of a layout is a creative exercise • Maximum Flexibility • Maximum Co-ordination • Maximum visibility • Maximum Accessibility • Minimum distance • Minimum handling • Minimum discomfort • Inbuilt safety • Efficient process flow • Identification
    • Basic Production Layout Formats 5 • Process Layout (also called job-shop or functional layout) • Product Layout (also called flow-shop layout) • Group Technology (Cellular) Layout • Fixed-Position Layout (Static Layout) • Service Layouts
    • Process Layout: Interdepartmental6 Flow • Given • The flow (number of moves) to and from all • • • departments The cost of moving from one department to another The existing or planned physical layout of the plant Determine • The “best” locations for each department, where best means maximizing flow, which minimizing costs
    • 7 Process Layout Advantages : • Reduced investment on m/cs – as they are general purpose • Production flexibility • Maximum utilization of men and machines • Easier maintenance Disadvantages • Difficulty in materials movement • Layout requires more space • Production time is more as WIP has to travel from point to point in search of the machines • Accumulation of WIP at different locations Developing a process layout • Graphic and schematic analysis – templates and two – dimension cutouts of equipments drawn to scale are the layout planning tools. • Computer models – CRAFT (Computerized Relative Allocation of Facilities Technique) • Load Distance Model- used to minimize the material flow
    • Process Layout: CRAFT Approach • It is a heuristic program; it uses a simple rule of thumb in making evaluations: • "Compare two departments at a time and exchange them if it reduces the total cost of the layout." • It does not guarantee an optimal solution • CRAFT assumes the existence of variable path material handling equipment such as forklift trucks (Computerized Relative Allocation of Facilities Technique) • 8
    • 9 Product Layout Advantages • Avoids production bottlenecks • Economy in manufacturing time • Requires less floor area per unit of production • WIP reduced – consequently less inventories. • Greater incentive to group of workers to raise their level of production. Disadvantages • Layout is known for inflexibility • Expensive layout • Lesser scope for expansion • M/c breakdown along the production line can disrupt the whole system. Developing a product layout • Line Balancing • Mixed – model Line balancing
    • Assembly Lines – different configurations • Materials Handling Devices – Belt or Roller Conveyors / • • • • • Overhead Cranes Line Configuration – Straight Line / U-shaped / Branching Pacing – Mechanical / Human Product Mix – One Product / Multiple Products Workstation Characteristics – Workers may sit / stand / walk with the line Length of the Line – Few Workers / Many Workers
    • Assembly Lines Balancing Concepts Question: Suppose you load work into the three work Question: Suppose you load work into the three work stations below such that each will take the corresponding stations below such that each will take the corresponding number of minutes as shown. What is the cycle time of number of minutes as shown. What is the cycle time of this line? this line? Station 1 Station 2 Station 3 Minutes 6 7 3 per Unit Answer: The cycle time of the line is always Answer: The cycle time of the line is always determined by the work station taking the longest determined by the work station taking the longest time. In this problem, the cycle time of the line is 7 time. In this problem, the cycle time of the line is 7 minutes. There is also going to be idle time at the minutes. There is also going to be idle time at the other two work stations. other two work stations. 11
    • 12 Example of Line Balancing  You’ve just been assigned the job of setting up an electric fan assembly line with the following tasks: Task A B C D E F G H Time (Mins) 2 1 3.25 1.2 0.5 1 1 1.4 Description Assemble frame Mount switch Assemble motor housing Mount motor housing in frame Attach blade Assemble and attach safety grill Attach cord Test Predecessors None A None A, C D E B F, G
    • 13 Example of Line Balancing: Structuring the Precedence Diagram Task Predecessors A None B A C None D A, C A Task Predecessors E D F E G B H F, G B G H C D E F
    • 14 Example of Line Balancing: Precedence Diagram Question: Which process step defines the maximum Question: Which process step defines the maximum rate of production? rate of production? 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 1.4 H Answer: Task C is the cycle time of the line and Answer: Task C is the cycle time of the line and therefore, the maximum rate of production. therefore, the maximum rate of production.
    • 16 Example of Line Balancing : Determine Cycle Time Question: Suppose we want to assemble Question: Suppose we want to assemble 100 fans per day. What would our cycle 100 fans per day. What would our cycle time have to be? time have to be? Answer: Answer: Production time per period Required Cycle Time, C = Required output per period 420 mins / day C= = 4.2 mins / unit 100 units / day
    • 17 Example of Line Balancing: Determine Theoretical Minimum Number of Workstations Question: What is the theoretical minimum number of Question: What is the theoretical minimum number of workstations for this problem? workstations for this problem? Answer: Answer: Theoretical Min. Number of Workstations, N t Sum of task times (T) Nt = Cycle time (C) 11.35 mins / unit Nt = = 2.702, or 3 4.2 mins / unit
    • 18 Example of Line Balancing: Rules To Follow for Loading Workstations  Assign tasks to station 1, then 2, etc. in sequence. Keep assigning to a workstation ensuring that precedence is maintained and total work is less than or equal to the cycle time. Use the following rules to select tasks for assignment.  Primary: Assign tasks in order of the largest number of following tasks  Secondary (tie-breaking): Assign tasks in order of the longest operating time
    • 19 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 1.4 H Task A C D B E F G H Station 2 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3
    • 20 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 A (4.2-2=2.2) 1.4 H Task A C D B E F G H Station 2 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3
    • 21 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 A (4.2-2=2.2) B (2.2-1=1.2) 1.4 H Task A C D B E F G H Station 2 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3
    • 22 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) Idle= .2 1.4 H Task A C D B E F G H Station 2 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3
    • 23 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) Idle= .2 1.4 H Task A C D B E F G H Station 2 C (4.2-3.25)=.95 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3
    • 24 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 1.4 H Task A C D B E F G H Station 2 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) C (4.2-3.25)=.95 Idle= .2 Idle = .95 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3
    • 25 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 1.4 H Task A C D B E F G H Station 2 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) C (4.2-3.25)=.95 Idle= .2 Idle = .95 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3 D (4.2-1.2)=3
    • 26 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 1.4 H Task A C D B E F G H Station 2 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) C (4.2-3.25)=.95 Idle= .2 Idle = .95 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3 D (4.2-1.2)=3 E (3-.5)=2.5
    • 27 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 1.4 H Task A C D B E F G H Station 2 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) C (4.2-3.25)=.95 Idle= .2 Idle = .95 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3 D (4.2-1.2)=3 E (3-.5)=2.5 F (2.5-1)=1.5
    • 28 2 A 1 B 1 G C D E F 3.25 1.2 .5 1 Station 1 1.4 H Task A C D B E F G H Station 2 A (4.2-2=2.2) B (2.2-1=1.2) G (1.2-1= .2) C (4.2-3.25)=.95 Idle= .2 Idle = .95 Followers 6 4 3 2 2 1 1 0 Time (Mins) 2 3.25 1.2 1 0.5 1 1 1.4 Station 3 D (4.2-1.2)=3 E (3-.5)=2.5 F (2.5-1)=1.5 H (1.5-1.4)=.1 Idle = .1 Which station is the bottleneck? What is the effective cycle time?
    • 29 Example of Line Balancing: Determine the Efficiency of the Assembly Line Sum of task times (T) Efficiency = Actual number of workstations (Na) x Cycle time (C) 11.35 mins / unit Efficiency = =.901 (3)(4.2mins / unit)
    • 30 Cellular Manufacturing layout • Machines are grouped into cells and the cells • • • • function somewhat like a product layout within a larger process layout. Each cell in this layout is formed to produce a single parts family Lower WIP inventories, reduced materials handling costs, simplified production planning Improved on time delivery Improved Quality.
    • Cellular Manufacturing layout Cell # 1 1 5 2 Cell # 2 1 2 Part D 3 Part X Part Y 4 1 Part A Part B 3 1 2 2 3 Cell # 4 4 Production operation Cell # 3 Product or materials
    • 32 Group Technology: Benefits 1. Better human relations 2. Improved operator expertise 3. Less in-process inventory and material handling 4. Faster production setup
    • 33 Group Technology: Transition from Process Layout 1. Grouping parts into families that follow a common sequence of steps 2. Identifying dominant flow patterns of parts families as a basis for location or relocation of processes 3. Physically grouping machines and processes into cells
    • 34 Fixed Position Layout Question: What are our primary considerations Question: What are our primary considerations for a fixed position layout? for a fixed position layout? Answer: Arranging materials and equipment Answer: Arranging materials and equipment concentrically around the production point in concentrically around the production point in their order of use. their order of use.
    • 35 Fixed position layout or Static layout  Involves the movement of men and machines to the product which remains stationery. Raw materials Machines Equipments Labour Finished Product (Aircraft)
    • 36 Service facility layout    Two different types of service facility layouts exist – based on the degree of customer contact. A) Layout which is totally designed around the customer receiving service functions. (Eg Banks, Fast food joints etc.) B) Layout which is designed around technology, processing of materials and production (Eg. Hospitals, Restaurants etc.)
    • Hospital Wards Hospital wards Hospital Wards Suregery, Radiology, Intensive Care and Technical Services Doctors Lounge/ Offices Hospital Wards Parking Area Parking Area Casualty Department and Inpatient Department Nureses Lounge/ Offices Cafetaria Parking Area Entrance Exit Service facility layout (Hospital Layout) Parking Casualty Department and Inpatient Department Aisles/Gangways Parking Area Exit Parking Entrance
    • 38 Retail Service Layout Goal--maximize net profit per square foot of floor space  Servicescapes  – Ambient Conditions – Spatial Layout and Functionality – Signs, Symbols, and Artifacts
    • 39 Question Bowl Which of the following are distinguishing features of CRAFT? a. It is an optimization methodology b. Does not require any assumptions about the layout or inter-relationships of departments c. Can handle over 50 departments d. All of the above e. None of the above Answer: e. None of the above (It is a heuristic program, does not guarantee an optimal solution, requires layout assumptions and can handle up to 40 departments.)
    • 40 Question Bowl Which of the following is a process that involves developing a relationship chart showing the degree of importance of having each department located adjacent to every other department? a. Systematic layout planning b. Assembly-line balancing c. Splitting tasks d. U-shaped line layouts e. None of the above Answer: a. Systematic layout planning
    • 41 Question Bowl If the production time per day is 1200 minutes and the required output per day is 500 units, which of the following will be the required workstation cycle time for this assembly line? a. 2.4 minutes b. 0.42 minutes c. 1200 units d. 500 units e. None of the above Answer: a. 2.4 minutes (1200/500=2.4 minutes)
    • 42 Question Bowl You have just finished determining the cycle time for an assembly line to be 5 minutes. The sum of all the tasks required on this assembly is is 60 minutes. Which of the following is the theoretical minimum number of workstations required to satisfy the workstation cycle time? a. 1 workstation b. 5 workstations Answer: c. 12 c. 12 workstations workstations d. 60 workstations (60/5=12) e. None of the above
    • 43 Question Bowl If the sum of the task times for an assembly line is 30 minutes, the actual number of workstations is 5, and the workstation cycle time is 10 minutes, what is the resulting efficiency of this assembly line? a. 0.00 b. 0.60 c. 1.00 d. 1.20 e. Can not be computed from the data above Answer: b. 0.60 (30/(5x10)=0.60)
    • 44 Question Bowl Which of the following are ways that we can accommodate a 20 second task in a 18 second cycle time? a. Share the task b. Use parallel workstations c. Use a more skilled worker d. All of the above e. None of the above Answer: d. All of the above
    • 45 Question Bowl Which of the following are “ambient conditions” that should be considered in layout design? a. Noise level b. Lighting c. Temperature d. Scent e. All of the above Answer: e. All of the above
    • 46 Solved Problems – OPERATIONS MANAGEMENT (Class of 2010) Q2. A toaster assembly line has to turn out 50 toasters per hour. The tasks, their times and their immediate predecessors are shown in the table below. (10 Marks) Task A B C D E F G H I J K L M Time, secs Imm Pred 28 35 29 32 28 45 37 31 36 42 49 52 37 ---A A C C C E,F D,G H H H J,K L
    • 47 Design a line to meet the above production rate, and show your design as a diagram in the template given below, writing task letter above the work-station numbers. Remember to fill in the cycle time and efficiency boxes. Cycle time, secs: Work Station: 1 Answer. a) 2 Line efficiency, %: 3 4 5 6 Assembly Line Balancing Expected Cycle Time = 1 Throughput Rate = 60 minutes 50 = 1.2 minutes = 72 secs. / Toaster 7 8 9 10 11
    • 48 b) Now, workout the Total Task Time Task A B C D E F G H I J K L M Total c) Time, secs Imm Pred 28 35 29 32 28 45 37 31 36 42 49 52 37 481 ---A A C C C E,F D,G H H H J,K L Theoretical no of Workstations Required (for maximum efficiency) = Total Task Time Cycle Time
    • 49 = 481 72 = 6.68 = 7 workstations d) Now, draw the Precedence Diagram (Note:- Let us denote “O” as an Activity) B 35 A 28 C 29 D 32 F 45 H 31 E 28 G 37 I 36 J 42 K 49 Terminal Point L 52 M 37
    • 50 Note:- As there are no successor of activities B and I, we assume that all three activities B,I and M will meet at a Termination Point. So, as soon as activity M gets completed, all of them will meet at a Termination Point e) Now, sequencing as per no of followers Task (Activity) A B C D E F G H I J K L M No. of followers 12 0 10 6 7 7 6 5 0 2 2 1 0
    • 51 f) Now, grouping them in descending order of their follower numbers Tasks A C E,F D,G H J,K L B,I,M Followers 12 10 7 6 5 2 1 0
    • 52 g) Now, realign them on the basis of maximum time taken Task A C F E G D H K J L M I B Time 28 29 45 28 37 32 31 49 42 52 37 36 35
    • 53 h) Now, we have to regroup them such that their total time does not exceed the cycle time Workstation W1 W2 W3 W4 W5 W6 W7 W8 W9 Task A,C F E,G D,H K J L M I,B Total Time (secs) 57 45 65 63 49 42 52 37 71
    • 54 i) Diagram in the template Given 100 90 80 70 60 Time 50 (secs) 40 30 57 45 65 63 49 42 52 37 71 20 10 WS1 WS2 WS3 WS4 WS5 WS6 WS7 WS8 WS9 Workstation (WS)
    • 55 j) Therefore the no. of Workstations required (N) = 9 However, we found out initially, for maximum efficiency, we need 7 (approx.) Workstations Therefore Line Efficiency = (where ∑ T = 7 C and ∑T C×N N = 9) Therefore Line Efficiency = 7 ×100 = 77.78 % 9 k) Cycle time, secs = 72 Line Efficiency, % = 77.78
    • 56 Alternate Answer to Q.2 Task A C E F D G H J K L B I M No.of Followers (descending order) 12 10 7 7 6 6 5 2 2 1 0 0 0 Rank Order of Task 1 2 3 3 4 4 5 6 6 7 8 8 8 A C F E G D H K J L M I B Time Required (secs) 28 29 45 28 37 32 31 49 42 52 37 36 35 Workstation Grouping (Time should not exceed 72 secs) W1 W2 W3 W4 W5 W6 W7 W8 W9
    • 57 Note : When there are two tasks with the same ranking, then place the task with the higher cycle time first Diagram in the Given Template 71 65 57 72 secs 45 63 52 49 G 42 H 37 C F A E D K J WS1 WS2 WS3 WS4 WS5 WS6 Workstation (WS) I L M B WS7 WS8 WS9