1 HND UNIT 1 BUSINESS MANAGEMENT TECHNIQUES CRITICAL PATH ANALYSIS

*HND UNIT 1

BUSINESS MANAGEMENT TECHNIQUES

CRITICAL PATH ANALYSIS

*Critical path analysis (CPA) is a powerful tool to help you schedule and manage complex projects.

History

Developed in the 1950s to control large defence projects and has been used ever since.

CRITICAL PATH ANALYSIS

*CRITICAL PATH ANALYSISCPA enables you to: Lay out all tasks that must be completed as part of a project; Provide a basis for the preparation of schedules and resource planning;

Allows you to monitor achievement of goals; Helps you to see remedial action required to get a project back on course.

*Advantages of CPA over Gantt ChartsFormally identifies tasks, which must be completed on time for the whole project to be completed on time.

Identifies tasks, which can be delayed for a while if resources need to be allocated to catch up on missed tasks.

Identifies the minimum length of time to complete a project.

It helps to identify which tasks need to be accelerated if you need to run an accelerated programme.

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Disadvantages of CPA over Gantt Charts

Relation of tasks to time is not immediately obvious i.e. no timeline. Therefore CPA charts are more difficult to understand if you are not familiar with technique.

*Activity

Is a task or function that consumes time and other resources.

Event

Consumes no resources, especially no time. An event can be considered to represent a point in time or the representation of the status of a project at a particular instance i.e. project starts.

CPA chart nomenclature

*Drawing a CPA chartList all activities in the planShow the earliest start dateEstimate the length of time for each taskDetermine whether the tasks are parallel or sequential. If sequential show what task they are dependent upon.Plot the activities in a graphical depiction of the project i.e. tasks that make up the project and the logical relationships between them represented by symbols

*There are two types of logic diagrams:-

Types of Diagram Circle and arrow. Precedence diagrams.

*Arrow Diagrams

Diagram is made out of arrows and nodes plus numbers and letters for calculation and labelling purposes.

The arrows represent the actual activity of task. The nodes represent the point in time (event) when activities start and finish.

*Precedence Diagrams

Activities are shown as nodes. Arrows represent activity links or logical relationships. Activity links can have lead times i.e. paint drying etc, links consume no other resource than time. Lead times can be zero positive or negative.

*Diagram differencesThe two diagrams are fundamentally different in the methods of graphically representation but they depict the same information. However precedence diagrams are considered easier to develop and understand.

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PRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION

ACTIVITY DESCRIPTION

EARLIEST FINISH

CRITICAL PATHSLACK TIME

LATESTFINISH

*PRECEDENT DIAGRAMINSERT DESCRIPTION OR NUMERICAL VALUES

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

*PRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

FINISH TO START - MOST COMMON

*START TO STARTPRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

*PRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

START TO FINISH

*PRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

FINISH TO FINISH

*PRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

FINISH TO START WITH PRECEDENT

PRECEDENT TIME

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*PRECEDENT DIAGRAM

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

EARLIEST START

LATEST START

DURATION


EARLIEST FINISH


LATESTFINISH

*Early start (ES) - the point in time that all preceding activities have been completed.

Early finish (EF) - the earliest that all work started with an early start can be completed. EF = ES + D

Late finish (LF) - the point in time that all work involved in the activity must be completed in order to avoid delaying subsequent activities.

Late Start (LS) - the point in time by which an activity must be started in order to avoid delay to following activities. LS = LF-D

Project Duration (D) - is the aggregate combination of all the activities along the critical path of the project.

Activity Times

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Is the path representing the combination of activities any one which delayed will cause a delay to the project.

It is the longest time through the network.

Critical activities have zero total float.

Critical path

*Total float

Total float or slack time is the amount of time by which the start or finish of an activity can be delayed without delaying the project completion.

TF = ES LF D, or TF = LF EF, or TF = LS - ES (PREFERRED OPTION)

*Free float

The maximum amount of time that an activity can be delayed beyond its early start without delaying the early start of any other activity immediately following that activity. FF = ES succeeding - EF preceding

*Networks have to be solved in two passes a forward pass and a backward pass.

Dangling activities - all activities should have at least one preceding activity and at least one succeeding activity except from start and finish.

Lines CANNOT cross one another and should minimise clutter.

Some Rules of Logic Diagrams

*Time - working days i.e. overall duration

Man days - days people work

Paint drying days

Money costs sales and profit

Raw materials

Actual numbers of peopleEstimating Resources

*Man-daysAre the number of people performing an activity multiplied by the working day or duration.The number of days that an activity will take until completed.

To identify these requirements a number of estimating techniques must be used.

*Comparative estimates - use data from comparable projects i.e. against figures recorded cost +/-15%

Feasibility estimates - total quotations for each component part.

i.e. you can calculate how much paint a ship will require to be fully coated with a primer, base coat and top coat.

ESTIMATING TECHNIQUES

*ESTIMATING TECHNIQUESBallpark estimates - are based on judgement and luck. +/- 25%.Percentage estimates - are models based on progress to date compared with other projects.i.e. - At this point in time I have spent 10 and I am 10% through the project hence project costs are 100.

*Ballpark Twice the optimistic plus four times pessimistic add the most likely and divide by 7Weight time estimatesTeam experience/sizeif very experienced reduce estimates by 10%If limited experience add 10%

Rules of

*Rules of

Customer support/understanding Great support reduce by 10% Limited support add 10% Little support add 20% Novelty of project If some new add 10% If all new add 20%

*Rules ofNumber of customers involved or number of organisations If 2 add 10% If 3-4 add 20% If 5 or more add 40%

*Percentage of time spent on other work by a team member

10-30% add 10% to estimates30-50% add 20%More than 50% add 30%

Project plan complexityIf simple reduce by 10%If very complex add 10%

Rules of

*Is a variation on critical path analysis. It takes a more sceptical view of time estimated for each stage.

Time for a project stage:-

(shortest time + 4) x (likely time + longest time) 6It helps to refocus timescale needed, by giving a reasonable estimation of time rather than the unrealistically short timescale normally assumed/DEMANDED.Programme Evaluation and Review Technique (PERT)

*SETTING OUT THE ANALYSIS AND DUMMY ACTIVITIES

* Layout a rough diagram of the project/Task flow.

Ensure that you have the order of project activity shown in the correct order.

Label activities A,B etc.

In an exam you will be given numerical values.

SETTING OUT THE ANALYSIS AND DUMMY ACTIVITIES


Connect activities together using flow lines

REMEMBER that flow lines cannot cross. Think of the analysis as a pipeline diagram or piping system pumping many DIFFERENT types of fluid. Different fluids cannot travel in the same pipe andcannot cross connect.

*Start with a START ( EVENT) box and finish with a FINISH (EVENT) box

If lines cross connect use a DUMMY box, an EVENT blank box, to connect the paths.



Analyze the project time thus:- Start box Box A Start time plus duration =finish time Box B Start time = previous box finish time. Finish time = start time plus duration etc.

*NOTESometimes between boxes you have a PRECEDENCE time: this refers to a SLACK time period that occurs after an ACTIVITY/Task has finished

Typically this could be: paint drying, concrete setting, waiting for tides etc.

This precedent must be added on to the end of the previous activity in order to evaluate total time.

When more than one previous activity connect to the next box, then the HIGHEST finish time becomes the next start time.


*Project time is evaluated by ADDING duration time, going from left to right, to arrive at the highest number for evaluating the project time.

LOWEST + DURATION = HIGHEST

CRITICAL PATH ANALYSIS is established by moving from right to left and using the highest number as a start point and SUBTRACTING duration time to arrive at LATEST START TIME and thus assess SLACK TIME.

When SLACK Time is ZERO, then this activity is CRITICAL and you have found a CRITICAL path.

ANALYSIS

CAR PURCHASE

Critical Path Analysis is an effective and powerful method of assessing:-

CAR PURCHASE

CAR PURCHASE

CONCLUSION What tasks must be carried out. Where parallel activity can be performed. The shortest time in which you can complete a project . Resources needed to execute a project. The sequence of activities, scheduling and timings involved. Task priorities- reallocation of resources. The most efficient way of shortening time on urgent projects.

*CONCLUSIONAn effective Critical Path Analysis can make the difference between success and failure on complex projects.

It can be very useful for assessing the importance of problems faced during the implementation of the plan.

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1 HND UNIT 1 BUSINESS MANAGEMENT TECHNIQUES CRITICAL PATH ANALYSIS