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transcript
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Introduction to Work Design
TOOLS
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METHODS STUDY
Systematic recording of existing and
proposed ways of doing work in order to
simplify the job Improve procedures
Improve layout
Reduce human fatigue
Improve use of materials, machines, labor
Improve physical workplace
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Fig. 2.1 Steps in Methods Study
1) Select project
2) Get and present data
3) Analyze data
4) Develop ideal method
5) Present and install method
6) Develop job analysis
7) Establish time standards
8) Follow up
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Fig. 2.1 Steps in Methods Study
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#1 Select Project
Human factors
Technical factors
Economic factors Exploratory tools
Pareto analysis
Gantt chart Fish diagram
Job/Worksite Analysis Guide
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PARETO ANALYSIS (80-20 Rule)
Vilfredo Pareto economist
80% of money held by 20% of people
80% of costs, accidents, injuries,accounted for by 20% of jobs/individuals
Concentrate on those 20%
Plot in descending order as a cumulativeprobability distribution (DesignTools)
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GANTT CHART
Horizontal bar chart of activities
Shade in bar as completed
Any given point in time, a snapshot of thestatus of all activities
Some behind, some ahead of schedule
Again focus efforts where needed Use DesignTools
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JOB/WORKSITE
ANALYSIS GUIDE
Time to go out on the floor
M
eet with supervisor first Explain study (production?)
Select jobs/workers
May need to meet with union also
Never express opinions
Fill out Job/Worksite Analysis Guide
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LABELING OPERATION
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METHODS STUDY (NEXT?)
2) Get and present data
3) Analyze data
4) Develop ideal method
All of these overlap
Use special charts or
procedures
Quicker, more efficient Designed specifically for IEs
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Charts using sequence only
Operation (outline) process chart Flow process chart
Two-hand process chart
Charts using time
Multiple activity chart Simo chart
Charts indicating movement
Flow diagram
Travel chart
Motion analysis
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PROCESS CHARTS
Record sequence of flow for worker,
material, or tools/machines
Outline (operation) vs flow
Supply basic information: date, job, worker
ASME symbols for activities (shorthand)
Vertical lines main flow
Horizontal lines subcomponents to main
Summary compare before and after
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PERT chart
A PERT chart is a project management toolproject management tool used to
Schedule
organize, and
coordinate tasks within a project.
PERT stands forProgram Evaluation ReviewTechnique, amethodology developed by the U.S. Navy in the 1950s tomanage the Polaris submarine missile program.
A similar methodology, the Critical Path Method(CPM) wasdeveloped for project management in the private sector atabout the same time.
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PERT chart
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PERT chart
A PERT chart presents a graphic illustration of a project as anetwork diagram consisting ofnumberednumbered nodesnodes (eithercircles or rectangles) representing events, or milestones in theproject linked by labeled vectors (directional lines)representing tasks in the project.
The direction of the arrows on the lines indicates the
sequence of taskssequence of tasks. In the diagram, for example, the tasks between nodes 1, 2, 4, 8,
and 10 must be completed in sequence.
These are called dependentorserialtasks.
The tasks between nodes 1 and 2, and nodes 1 and 3 are not
dependent on the completion of one to start the other and canbe undertaken simultaneously.
These tasks are called parallelorconcurrenttasks.
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PERT chart
The PERT chart is sometimes preferred overthe Gantt chart, another popular projectmanagement charting method, because it
clearly illustrates task dependencies. On the other hand, the PERT chart can be
much more difficult to interpret, especially oncomplex projects.
Frequently, project managers use bothtechniques.
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How to use it: Identify all tasks or project components.Make sure the team includes people with firsthand
knowledge of the project so that during the brainstorming session all component tasks needed
to complete the project are captured. Document the tasks on small note cards. Identify the first task that must be completed. Place the appropriate card at the extreme left
of the working surface.
Identify any other tasks that can be started simultaneously with task #1. Align these taskseither above or below task #1 on the working surface.
Identify the next task that must be completed. Select a task that must wait to begin until task#1(or a task that starts simultaneously with task #1) is completed. Place the appropriate card tothe right of the card showing the preceding task.
Identify any other tasks that can be started simultaneously with task #2. Align these taskseither above or below task #2 on the working surface.
Continue this process until all component tasks are sequenced.
Identify task durations. Using the knowledge of team members, reach a consensus on themost likely amount of time each task will require for completion. Duration time is usuallyconsidered to be elapsed time for the task, rather than actual number of hours/days spent doingthe work. Document this duration time on the appropriate task cards.
Construct the PERT chart. Number each task, draw connecting arrows, and add task
characteristics such as duration, anticipated start date, and anticipated end date. Determine the critical path. The projects critical path includes those tasks that must bestarted or completed on time to avoid delays to the total project. Critical paths are typicallydisplayed in red..
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PERT EXAMPLE
Fill in earliest possible start time for each event inside the circle
Find the critical path. Mark it with dark lines on the figure, or list the
sequence of arcs.
What is the total project duration (in weeks)?
HW1 due next week
C-1
D-2
F-5
B-3
A-4 E-4
Start
End
$ 100
$ 150
$ 300
$ 600$ 110
$ 500
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Gantt chart
A Gantt chart is a horizontal bar chart developed as aproduction control tool in 1917 by Henry L. Gantt, an
American engineer and social scientist.
Frequently used in project management, a Gantt chartprovides a graphical illustration of a schedule thathelps to plan, coordinate, and track specific tasks in aproject.
Gantt charts may be simple versions created on graphpaper or more complex automated versions createdusing project management applications such asMicrosoft ProjectMicrosoft Project orExcel
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Gantt chart
A Gantt chart is constructed with a
horizontal axis representing the total
time span of the project, broken
down into increments (for example,
days, weeks, or months) and avertical axis representing the tasks
that make up the project (for
example, if the project is outfitting
your computer with new software,
the major tasks involved might be:
conduct research, choose software,install software).
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Gantt chart
Horizontal bars of varying lengths represent the sequences,timing, and time span for each task.
Using the same example, you would put "conduct research" atthe top of the vertical axis and draw a bar on the graph that
represents the amount of time you expect to spend on theresearch, and then enter the other tasks below the first one andrepresentative bars at the points in time when you expect toundertake them.
The bar spans may overlap, as, for example, you may conductresearch and choose software during the same time span.
As the project progresses, secondary bars, arrowheads, ordarkened bars may be added to indicate completed tasks, orthe portions of tasks that have been completed.
A vertical line is used to represent the report date.
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Gantt chart
Gantt charts give a clear illustration of project status, but oneproblem with them is that they don't indicate task dependencies- you cannot tell how one task falling behind schedule affectsother tasks.
The PERT chart, another popular project management chartingmethod, is designed to do this.
Automated Gantt charts store more information about tasks,such as the individuals assigned to specific tasks, and notesabout the procedures.
They also offer the benefit of being easy to change, which ishelpful.
Charts may be adjusted frequently to reflect the actual status ofproject tasks as, almost inevitably, they diverge from theoriginal plan.
Microsoft Project (.mpp)
You must use Gantt chart for your final project!
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MS Projectcan create a PERT chart from a Gantt chart. The PERT (next slide) is another representation of the Proposal project
shown above
The completed tasks have been crossed out while partially completed taskshave one slash through them.
The tasks also show duration, beginning date and ending date.
The critical path (shown in red) is a series of tasks that must be completedon schedule for a project to finish on schedule.
Each task on the critical path is a critical task. Most tasks in a typical projecthave some slack and can therefore be delayed a little without affecting theproject finish date.
Those tasks that cannot be delayed without affecting the project finish dateare the critical tasks.
As you modify tasks to resolve overallocations or other problems in yourschedule, be aware of the critical tasks and that changes to them will affectyour project finish date.
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Critical Path Method (CPM)
Critical Path Method (CPM) charts are similar to PERTcharts and are sometimes known as PERT/CPM.
In a CPM chart, the critical path is indicated.
A critical path consists that set of dependent tasks (eachdependent on the preceding one) which together take
the longest time to completelongest time to complete. Although it is not normally done, a CPM chart can define
multiple, equally critical paths.
Tasks which fall on the critical path should be noted insome way, so that they may be given special attention.
One way is to draw critical path tasks with a double lineinstead of a single line.
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Critical Path Method (CPM)
TasksTasks which fall on the critical path should
receive special attentionspecial attention by both the project
manager and the personnel assigned to them.
The critical path for any given method may shiftas the project progresses; this can happen when
tasks are completed either behind or ahead of
schedule, causing other tasks which may still be
on schedule to fall on the new critical path.