Line Balancing



	MCIE IIIL - Mixed Model Line Balancing System

(for JIT, work cell and assembly applications)

Introduction

Our new MCIE III-L Mixed-Model Line Balancing System is the best tool available today for dealing with the needs of Assembly in a modern production environment JIT, workcell production or other contemporary production techniques. Our system is easier to use than ever. It is icon driven and gives you all the horsepower of the mainframe system with the ease of use of a PC. A new line analysis takes only minutes to do, giving you unprecedented flexibility to do what-if's and generate information that will make your Simplified Synchronous production needs a simple task to satisfy. The MCIE III-L System is a computerized production management tool which provides Engineers with the ability to maximize productivity by reducing the idle time and evenly distributing the work among the least number of workers possible consistent with desired production levels in a JIT assembly or workcell production environment.

With the introduction of contemporary manufacturing methods such as Just-In-Time, Work cells and Process Plan control, the manufacturing engineer must be able to load the manufacturing facilities quickly and optimally on a regular basis. Because of Simplified Synchronous Production requirements, the problem he faces with these revisions is not the number of the revisions, but the timing of these changes. To be the most effective, the planning of new labor balance or loading of the facilities should be done as each new production plan is incorporated into the manufacturing system. This enables management to realize the most efficient labor cost on an assembly and a faster start for a return on his investment. MCIE III-L is the answer to these production needs. With MCIE III-L you will avoid costly mistakes and generate the information needed to engineer the right JIT or other production environment and give the shop floor all the documentation needed to do the manufacturing right the first time with the best use of resources and integration of production goals and constraints.

Our software system supplies a logical way to overcome the time consuming tasks required for a good JIT installation and proper workplace layout with workcells and Simplified Synchronous Production or special Assembly requirements.

Our software will:

     Provide engineering what-if simulation of proposed dedicated JIT lines, work cells or assembly lines for optimal engineering of production facilities.
     Reduce JIT production or assembly line Balance Delay.
     Load Facilities To Obtain Desired Schedules.
     Provide production restrictions while maintaining assembly line performance.
     Reduce Engineering work load.
     Produce Detailed Methods Instructions.
     Produce Tooling And Material Requirements.

The Planner Mixed Model and Production Schedule System

The MCIE III-L software includes the ability to balance a line which consists of a number of different product models in a mixed fashion. One record is used to identify each model and in this same record is indicated whether or not a particular balance is to apply to this model. This set of input data is to be used to balance a mixed-model production scenario.

The software for a mixed-model line balance will balance not only each station but each model within a station. For example a production schedule for the manufacture of an auto may have a mixed-model schedule of 26%, for the 2 door high line, 27% for the 2 door economy line and 47% for the 4 door high line. Our software will easily handle this type of production requirement, balancing the line for each of these components, while giving an overall balance for the line with this mix of products.

When using this type of mixed-model schedule, every element which is not required on all models must be defined as to which model or models require it. The program will then load each station with the factored time and each model with actual time. When the time for a model reaches the cycle time no more elements for that model will be added to the station.

An element model catalogue is used which contains records used to specify those FWE's which are required by the various models shown in the production schedule.

The MCIE III-L system requires five engineering steps to achieve a balance and generate the necessary control information for operation of the production line or assembly activity.

Step 1 - A determination is made of all tasks necessary to complete a production line or assembly activity. They are defined as Functional Work Elements (FWE's). An FWE is the smallest amount of work that can be completed by an operator without causing that task or any portion of it to recur.

Step 2 - Time values must be established for each FWE. These can be developed through UnivEl.

Step 3 - Construct a Precedence Diagram which includes Functional Work Elements (FWE's) This chart will include the FWE names and restrictions. Time values may be included if desired. This chart will represent how the product can be assembled.

Step 4 - Generate an engineer's balance. This will include determining the production schedule, model catalogue to be used, production restrictions, line definition, special allowances, and cycle ranges.

Step 5 - When a satisfactory balance has been achieved, output is generated which supplies the operator with a step-by-step methods description for each station with manning requirements, high station time and tools, materials, and drawings.

Overview of the MCIE III-L System

This software is a systematized approach to the problem of distribution of labor in a JIT, assembly or workcell production environment and is key to a properly functioning shop floor with efficient use of labor and other resources. It uses a set of rules that assign all operators a series of Functional Work Elements (FWE) so each operator has an equal amount of work to perform and maintains this balanced environment within a set of restrictions or bounds on the manufacturing plan. The following is a brief description of the steps to be taken in properly utilizing the MCIE III-L System: The MI Systems computerized line balance engineering software consists of two powerful planning and control systems:

1. THE PRODUCTION PLANNER. This system develops a station-by-station plan for the engineer's assembly or production line balance, using manufacturing production constraints on the line, time for assembly, model mix and other engineering parameters required for the proper production of the product.

2. THE PRODUCTION DETAILER. This system develops a station-by-station listing of the production elements required to build the product, such as assembly restrictions, order of assembly, materials, assembly procedures, station layout and other instructions or diagrams required to insure proper assembly of the product at the individual assembly workstation. It will also output a station-by-station listing of all materials, tooling and drawings of the involved parts required at the station.

There are three basic components necessary for the MCIE III-L system - precedence relationship, time, and restrictions - to solve the tasks of distribution of labor.

1. THE PRODUCTION PLANNER.

MCIE III-L may be used alone if elemental times have been developed by some means other than UnivEl. UnivEl can, however, be used to generate the elemental times and to format and output the data records that will make up the major portion of the input to both the PLANNER and DETAILER SYSTEMS.

To utilize UnivEl for Manufacturing Planning, the analyst must identify the FWE's in the UnivEl study. The analyst may also identify any material, tooling, or drawings to be listed at various stations in the OPERATOR DETAIL. The UnivEl program prints out a summary of the FWE's following the UnivEl output. It also stores on the computer the summaries and formatted lists of FWE definitions and Operator Detail. Information can be brought to the screen or printed in hard copy for use on the shop floor.

The first group of records becomes the element definition file for the PLANNER. The second group of records becomes the element description file, and the third group of records becomes the tooling, material and drawing records for the DETAILER.

The Planner Precedence Diagram

Our software uses precedence diagramming to define the set of operations to be followed in the production plan. The technique, which has evolved for solving the problem of production steps in a line environment, is called precedence diagramming. Precedence diagramming is a graphical method of network analysis which shows all possible combinations of the assembly or JIT production procedure. The diagram gives a logical and systematic presentation of precedence relationships. Also, it provides a clear understanding of the JIT production or assembly line and can serve as a training aid for new engineers.

The Planner Manufacturing Restrictions

The software contains bounding parameters called Manufacturing restrictions which are applied to assembly production elements when various tasks have manufacturing requirements which do affect the scheduling and configuration of the JIT production or assembly line. An example would be a piece of equipment on the line that cannot be moved. Certain elements must be done at the station where that piece of equipment is located. Another example would be where more than (1) operator is required to perform or complete a task. Our software allows the engineer to include these restrictions easily and with flexibility.

When conditions such as these exist, the engineer can label certain elements with the necessary manufacturing restrictions, thus controlling the assignment of those elements.

The following manufacturing restrictions can be placed on the line balance: Assign, Workplace, Unit Position, Element Grouping, Element Degrouping, Null, Always Used Together, Co-OP, Special Assign, and Add. Each of these are discussed briefly below.

Assign Manufacturing Restriction

The Assign restriction can be used to assign certain work elements to a particular station or to one of a group of stations or to exclude certain work elements from a particular station or group of stations.

Workplace Restriction

The Workplace restriction can be used to restrict the assignment of work elements to a station or stations where the workers position is suitable to performing the work.

For example, you might have stations on both sides of a conveyor and wish to restrict certain work elements to one side or the other. This can be accomplished by using a combination of workplace manufacturing restrictions and station specification records.

The program will assign elements carrying any of these workplace names only to stations that have been specified as being manned in one of these positions.

Unit Position Restriction

In certain assembly situations, the present position of the unit being assembled may make it difficult or even impossible to perform certain work elements.

The unit position restriction can be used to prevent the assignment of any work element to a station where the unit is in an improper position. Any elements which do not carry a 'unit position' restriction can be performed when the unit is in any position.

The purpose of this restriction is to group elements of like position and automatically add additional time whenever the position of the unit is changed by the program.

If there are elements yet to be assigned that have no unit position restrictions, they will be assigned consistent with their order of precedence and other restriction types.

If and when the position of the unit is changed, additional time will be added to the station where the change occurs.

Grouping Restriction

In certain assembly situations it is desirable to group elements together for a number of reasons; the activity, physical layout, machine limitations, etc. This can be accomplished by using the grouping restriction.

As soon as an element carrying this type of restriction is added to a station, other elements carrying the same restriction name will be added to that station or following stations.

Element Degrouping Restriction

In certain situations it may be necessary or desirable to separate two classes of work such as packing bearings with grease and applying a pressure-sensitive label. The element degrouping restriction can be used to assure that these two classes of work are never assigned at the same station.

In certain situations it may be necessary or desirable to delete a restriction(s) from a previous line balance attempt. One /NULL/ restriction record can be used to suppress an active restriction that had been on many element definition records.

Special Assign Restriction

In many JIT production or assembly line situations it is not only desirable but often essential, because of part weight and other factors, that one operator assist another in the performance of various tasks. Our software contains manufacturing restrictions which give the engineer the capability to assure that these tasks are assigned to the proper work stations whether these stations be adjacent to each other on the same side of the line or on opposite sides of the line.

After the controlling element has been assigned to a particular station, the program assigns all elements that carry the special assign restriction to the next station.

Workplace Time Modifications

In some situations, it may be necessary to add additional elemental time to a particular work station when its workplace layout is changed. Our software can compensate for different workplace layouts when functional work elements are moved from station to station by the program to obtain the most desirable balance.

All stations are assumed by the program to be "normal", i.e.; manned by one person, whose workplace is on the left side of the line (looking down-line), and allowed no initial time allowance. However, one can also define "abnormal" stations.

2. BALANCING THE LINE

The program assigns those elements first which have no predecessors and highest time values. It next assigns those elements which have the most successors and highest time values. The program will stop adding elements to a station as soon as the low cycle parameter is reached. It will 'crowd' a station to the high cycle parameter however, to assure that shared elements and elements with group manufacturing restrictions are assigned to the proper stations.

Special Production Line Balance Modification Simulation.

Special element records are optional and are normally used to move elements from one station to another. The most common factors which cause a balance delay are elements which are assigned to the last station, elements with larger than average time, co-op manufacturing restrictions, and left and right hand station requirements. These elements can be moved from station to station in the operator detail without making another MCIE III-L run.

3. THE PRODUCTION DETAILER

Station-by-Station Operator Detail

Once an engineer has achieved a satisfactory JIT production or assembly line balance via the MCIE III-L program, that person can then generate a station by station operator detail. This is the document that is intended to be used on the shop floor since it has the capability of being much more detailed in regard to the assembly build procedure than the output from MCIE III-L. Besides being more detailed in method, it shows the high station time at each station, number of operators required, tools used, etc.

Detailer Shop Floor Production Notes

The system generates production notes which may be special instructions to the operator at each station or merely statements of a general nature. In any event it will be information not contained in the element descriptions.

Element Description Records may be used to describe the work elements for the individual station in greater detail than they appear on the standard MCIE III-L output. The remaining required records are then added to complete the operator detail file. The system then generates a station-by-station tooling, material, and drawing list. This information can be entered via UnivEl.

MCIE IIIL - Mixed Model Line Balancing System

(for JIT, work cell and assembly applications)

Introduction

The Planner Mixed Model and Production Schedule System

Overview of the MCIE III-L System