Explain string diagram with a neat sketch. 

2 Answers

Answer :

The string diagram is a scale plan or model on which a thread is used to trace and measure the path of workers, material or equipment during a specified sequence of events.

image

Use of string diagram

1) To trace the path of workers

2) To trace material and equipment

3) To measure path of worker , material , equipment

4) To find time required for processing

Answer :

String Diagram:

1. A string diagram is defined as a scale plan or model on which a thread is used to trace and measure the path of workers, materials or equipments during a specified sequence of events.

2. It is a special form of flow diagram in which a string or thread is used to represent the movements.

3. The purpose of using string is to measure the distance between the two movements.

4. Repetitive movement and too many paths make the flow diagram congested and it becomes difficult to understand.

5. The paths which are travelled more frequently calls for critical examination of the work points or movement.

6. A String diagram for a particular process is shown in following fig.


image

Related questions

Description : Explain various Robot configurations with neat sketch. 

Last Answer : Different Robot Configurations: Robots are being classified on the basis of their physical configuration and control systems adopted. These classifications are briefly described as below: [1] ... direction for vertical insertion tasks. It is basically used for the assembly purpose.

Description : Explain any two clamping devices with neat sketch

Last Answer : [1] Screw clamp:- It is particularly useful when a component is to be gripped on its edges. This arrangement insures easy machining of top surface of work piece. [2] Equalizing clamp: - It ... is operated by simply actuating the handle up or down which locks or unlocks the strap with the work.

Description : Name different types of material handling equipments used in industry. Explain any one with neat sketch.

Last Answer : Types of material handling devices 1.Trucks : i) Power lift : a. Fork lift b. elevating platform ii) Hand Lift. iii) Porters trolley. 2.Tractors and trailers 3. Hoist and cranes: ... bands can also be used. 5. Speed of belt normally ranges from 1 m/s to 70 m/s.

Description : Explain cylindrical locator with neat sketch 

Last Answer : Cylindrical locators: - Cylindrical locators are very useful when finely finished holes are available for the positioning of components. It is used for locating components having drilled holes. The cylindrical ... jig s body around the locator is undercut to provide space for swarf clearance

Description : Explain with neat sketch any two material handling devices used in mass production.

Last Answer : 1.Roller conveyors may be gravity aided or powered and are employed for transporting products having flat bottoms. Bigger jobs can be handled as they are, whereas small items are put in boxes, tins ... and unloading of the products.   4.Screw Conveyor, Pneumatic Conveyor, Elevated Conveyor . 

Description : Explain cylindrical configuration with neat sketch

Last Answer : Cylindrical Configuration:- These uses a vertical column and a slide that can be moved up and down along the column. The robot arm is attached to the slide so that it can be moved radially with ... column. By rotting the column the robot is capable of retrieving a cylindrical work envelope.

Description : List the types of locators and explain any one with a neat sketch.

Last Answer : 1) Adjustable locators ( Flat locators) 2) Cylindrical locators 3) Fixed V Locators 4) Conical locators 1) Flat Locator: -These are employed for locating flat machined faces of the component. ... . 5) V locator:-It is used for locating components having circular profile.

Description : Explain 3-2-1 principle of location with neat sketch.

Last Answer : 3-2-1 principle of location  It is also known as six pin or six point location principle. In this, the three adjacent locating surfaces of the blank (work piece) are resting against 3, 2 and 1 pins ... above method of locating a work piece in a fixture is called the 3-2-1 Principle  

Description : Explain product layout with a neat sketch. 

Last Answer : Product layout  1. This layout is also called flow-line layout, line layout or production line layout. In this layout, the machines, equipment and work centers are arranged in a straight or ... the other end of the line. 4. Examples are automobile assembly lines, bottling plant and so on

Description : Define plant layout. Explain in detail 'Process layout' with neat sketch.

Last Answer : Definition of Plant layout It is defined as the systematic arranging of various facilities like equipments, machines manpower, and inspection areas, etc and services within the area  of plant ... required for product manufacturing Less cost of investment General purpose machines are used

Description : Describe cylindrical body and arm assembly robot with neat sketch.

Last Answer : Cylindrical body robot: In the cylindrical configuration, robots have one rotatory (R) joint at the base and linear (L) joints succeed to connect the links. The space in which this robot ... in horizontal direction for vertical insertion tasks. It is basically used for the assembly purpose.

Description : Describe working of screw conveyor with neat sketch.

Last Answer : 1. A Screw conveyor consist of a continuous or broken blade helix or screw fastened to the shaft (or a pipe) 2. This helix or screw rotates in trough so that revolving screw advances the material. 3. ... divided solids or pasty solids. 4. This conveyor can also be used as mixture or blender. 

Description : State types of plant layouts. Describe product layout with neat sketch.

Last Answer : Types of plant layout: 1. Product or line layout 2. Process or functional layout 3. Fixed or static layout 4. Combination layout. Product layout: 1. This layout is ... line without back-tracking or cross-movements and finally the end product leaves from the other end of the line.

Description : Explain 3-2-1 principle of locations with suitable example and neat diagram

Last Answer : 3-2-1 Principle of Location used in Jig & Fixtures: It is also known as six pin or six point location principle. In this, the three adjacent locating surfaces of the blank (work piece) are ... [7] Another pin F in the second vertical face of the fixed body, arrests degree of freedom 9.

Description : What are the different types of Fixtures? Explain any one with sketch.

Last Answer : Types of Fixtures: Following are the types of Fixtures according to the type of machine operations for which they are used. [1] Lathe (Turning) Fixture [2] Milling fixtures  [3] Grinding ... relative to the tool of the machine table and guide the broaching tool in relation to the job. 

Description : List down various types of clamping devices used in design of Jigs. Explain any one with sketch.

Last Answer : List of Types of clamping devices used in design of jigs. i. Screw clamp ii. Pivoted clamp. iii. Equalizing clamp. iv. Latch clamp. v. Wedge clamp. vi. Hinged jaw clamp. ... to be gripped on its edges as shown in figure. This arrangement ensures easy machining of the work piece 

Description : State types of mechanical joints used in robots. Explain any one with sketch.

Last Answer : [1] Rotational joint [2] Linear joint [3] Twisting joint [4] Orthogonal & [5] Revolving joint Rotational Joint: Rotational joint can also be represented as R - Joint. This type will allow the ... to the rotational axes. As like twisting joint, the output link spins about the input link. 

Description : Explain spherical configuration with sketch.

Last Answer : Spherical configuration  Spherical Configuration: - It uses telescopic arm that can be raised or lowered about a horizontal pivot point. The pivot point is mounted on a rotating base and gives the ... joints provide the robot with the ability to move its arm within a spherical envelope.

Description : Explain the robot anatomy and structure with sketch. 

Last Answer : Robot Anatomy: Robot anatomy concerns with the physical construction and characteristics of the body, arm, wrist which are components of the robot manipulator. Most robots are mounted on a base. The body is ... 6. Drive: The drive is the motor that moves the links into their designated position.

Description : Draw proportionate sketch of template jig. State its use.

Last Answer : Use of Template jig:- 1) This jig avoids the marking operation completely 2) Drilling is done quickly 3) Easy and Fast loading and unloading of work pieces 4) For drilling flat work pieces they can be accommodated in this jig Sketch :-

Description : Draw the labelled sketch of turning fixture.

Last Answer : Figure: Back plate of Turning Fixture

Description : Enlist types of joints used in robotic arm and draw sketch of any two

Last Answer : Types of Joints [1] Linear Joint or Prismatic joint [2] Orthogonal Joint [3] Rotational joint [4] Twisting Joint [5] Revolving joint

Description : With the help of constructional diagram, explain the working of LDR with neat sketch.

Last Answer : Working Principle The resistance depends on the intensity of light, as resistance decreases with increase in light intensity. Characteristics Applications of LDR 1. They are often ... circuits, light intensity meters, for counting the packages moving on a conveyor belt, etc.

Description : Explain with neat sketch block diagram of optical fiber communication system and list out sources and detectors suitable for it.

Last Answer : OR 1. The light source is normally an infrared LED or LASER device which is driven by the current value from the V to I convertor. It emits light which is proportional ... optical energy electrical signal. The light detectors which are used as PIN photodiode and avalanche photo diode.

Description : Explain with neat sketch method of drawing displacement diagram for SHM of follower. 

Last Answer : The displacement diagram is drawn as follows for SHM of follower : 1. Draw a semi-circle on the follower stroke as diameter. 2. Divide the semi-circle into any number of even equal ... number of equal parts. 4. The displacement diagram is obtained by projecting the points as shown in Figure

Description : Explain working of ELCB with neat sketch diagram.

Last Answer : Earth Leakage Circuit Breaker(ELCB): Earth leakage circuit breaker is a safety device used in electrical installations with high earth impedance to prevent shocks and disconnect power under earth fault ... tripping in domestic installations with tripping time being as low as 25 msec.

Description : Explain single phasing preventer with neat sketch diagram.

Last Answer : Single phasing preventer: Single phasing preventers are generally used for small / medium capacity motors. Single phasing preventers are connected in secondaries of line CTs. These mainly contains ... command is given to circuit breaker or starter. Thus it protects motor from damage.

Description : Explain distance protection of transmission line with neat sketch diagram.

Last Answer : Distance protection of Transmission line: Distance protection scheme uses impedance relay. The relay operation is based on the impedance (or distance) between the relay and point of fault. Figure shows ... than ZL and impedance relay operates which operates the CB and line is protected.

Description : Explain Horn-gap lightning arrester with neat sketch diagram.

Last Answer : Horn Gap Type Lightning Arrester: It consists of two horn shaped metal rods A and B separated by a small air gap. The horns are so connected that distance between them gradually increases towards the ... being hot, moves up naturally along the horns. So it is elongated and naturally quenched.

Description :  Explain the concept of AGV? State it’s any two applications. 

Last Answer : AGV is the battery operated programmed vehicle, used to carry load from one location to another by following a prescribed path around the manufacturing floor. It is a driverless vehicle, ... System) 2) AGV material handling system is very suited to computer integrated manufacturing system  

Description : Explain in brief the allowances to be considered while estimating the standard time.

Last Answer : Allowances to be considered while estimating the Standard Time: Allowances are added to the normal time in order to arrive at standard time. It is impossible to work throughout the day even ... under exceptional circumstances. It is used with utmost care and only in clearly defined circumstances.

Description : What is ejector? Explain role and necessity of ejector in the design of jigs and fixtures.

Last Answer : Ejector: Ejector is used to remove the work piece from close fitted locators and is present behind the work piece. Ejector speed up the operation by reducing unloading time. This increases the ... [6] The combined mechanism used in Ejectors can be powered hydraulically or by compressed air. 

Description : Explain the concept of JIT and how does it help the manufacturing system to improve productivity?

Last Answer : Concept of JIT: [1] JIT is a Production methodology which aims to improve overall productivity through elimination of waste and which leads to improved quality. [2] JIT concept was ... ] It improves customer satisfaction [14] It improves working condition and relation between employees. 

Description : Explain the importance of ‘5S’ (“Five S”) Concept.

Last Answer : Introduction of 5 S Concept: [1] 5S is a process of workplace organization and housekeeping which is carried out gradually and systematically. [2] It is a structured program to implement workplace ... In fact, 5S is a basic step in a journey towards Total Quality Management (TQM).

Description : Explain the principle of working of hydraulic actuator and state its advantages.

Last Answer : Working Principle of Hydraulic Actuator  1. According to Pascal, when there is an increase in pressure at any point in a confined incompressible fluid, then there is an equal increase at every point in ... better performance than others. 3. Power to weight ratio of these actuators is high.

Description : Explain the following terms in context with work study.

Last Answer : i. Therbligs. ii. MTM (Method Time Measurement)  Therbligs :  1. Therbligs are used to describe the basic element of movement or fundamental hand motions of the work cycle. 2. Every ... sum of these motion times is the time an operator of average skill would take to perform the task.

Description : Explain the need and importance of material handling devices in an industry. 

Last Answer : Need of material handling devices: Material handling is an important activity in the industries. A large part of indirect labour employed in an industry is engaged in handling of materials. It has ... material handling and provides proper working conditions. 6. Reduced in process inventory.

Description : Explain the various steps for planning a process for product from raw material to finished product in an industry.

Last Answer : 1. Analysis of Product and its specification: - During analysis, following parameter should be considereda. Drawing and specification of product. b. Quality of product. c. Number of parts/components per ... and fixing the rates of payment. 11. Prepare the route sheet and operation sheet.

Description : Explain the design principles of plant layout.

Last Answer : Design Principles of Plant Layout: S.N. Design Principles Description 1 Principle of Integration All the plant facilities should be fully integrated into a single operating unit ... should be utilized in an optimum manner so as to result in minimum initial capital investment.

Description : Enlist any four factors which affect selection of material handling system. Explain which type of material handling system is suitable for: (i) Unloading two wheelers from truck ii) Stacking of pallets in store racks.

Last Answer : Four Factors affecting Selection of Material Handling System: [1] Adaptability and Flexibility [2] Type of Material to be handled [3] Type of Layout [4] Type of Production [5] ... [11] Cost of installation and handling Suitable Material Handling Devices for Following Activities:

Description : Explain how Gantt chart is used in project planning with proper example. 

Last Answer : Use of Gantt Chart in Project Planning: Gantt Chart is a project planning tool that can be used to represent the timing of tasks required to complete a project. Because Gantt chats are simple to ... a chart, which are used to record the actual operating times and delays of workers and machines.

Description : Explain the concept of production system with proper input output model.

Last Answer : Concept of Production System: The Production System of any organization is that part which produces the organizations products. [1] Production is the basic activity of any organization and all ... feedback system about the activities, which is essential to control and improve system performance.

Description : Explain tactile sensors in robots

Last Answer : Tactile Sensors:- Tactile sensors provide the robot with the capability to respond to contact forces between itself and other objects within its work volume. Tactile sensors can be divided ... magnitude of the contact force. Strain gauge devices are typically employed in force measuring sensors.

Description : Explain pull and push types of manufacturing system

Last Answer : Pull Type Manufacturing System: [1] Just in Time (JIT) is a pull system which is also known as Make to Order Production. [2] Pull System means that parts are produced to order and the ... represented by "Make to Stock" (MTS) in which the production is not based on actual demand.

Description : Explain in brief steps involved in process planning.

Last Answer : Steps involved in process planning: 1. Analysis of Product and its specification: - During analysis, following parameter should be considered, a. Drawing and specification of product. b. Quality of ... and fixing the rates of payment. 11. Prepare the route sheet and operation sheet.

Description : State and explain the basic principle to be followed to develop a good plant layout.

Last Answer : Following are the basic principle to be followed to develop a good plant layout. 1. Overall integration: A good layout is one that integrates men, materials, machine and supporting ... to the production process. For this purpose there must be sufficient space between different machines.

Description : How productivity is measured? Explain any one method of productivity measurement.

Last Answer : Measurement of productivity: - For measurement of productivity, one must find out input and output of the system. To measure the input resources and goods or services supplied is a critical job ... , cutting tools, coolant etc. Material productivity measures in terms of goods produced.

Description : What is meant by 5'S'? Explain each 'S' in details

Last Answer : 5 S' Concept:- 5'S is the name of a workplace organization methodology that uses a list of five Japanese words which are seiri, seiton, seiso, seiketsu and shitsuke constitute the system. ... Eliminate unwanted items. ➢ Maintain the discipline at work place ➢ Improved safety

Description : Explain various configurations with sketches

Last Answer : Robot Configurations 1) Rectangular Configuration:- This uses three perpendicular slides to construct the x, y, z axes. By moving three slides relative to one another, the robot is capable of ... , which provides a substantial rigidity in the vertical direction for many essential tasks.  

Description : Explain any one non tactile sensor used in robot

Last Answer : Non Tactile Sensor  [1] Vision Sensor: Robot vision is made possible by means of video camera, a sufficient light source and a computer programmed to process image data. The camera is mounted ... the input and the stored vocabulary word the robot performs some actions which correspond to the word.