Developing a Project Plan Chap 6 Developing a Project Plan

Developing a Project Plan Chap 6 The specific actions of the project are identified in the Work Packages The resources, time and cost have been identified, based on the work defined in the Work Packages. These costs have been assigned to a person or group identified in the Resource Allocation Matrix. Now it is necessary to identify the relationship of each activity. Which tasks must be started or completed before the next activity can begin. A network diagram is one method of showing this relationship

What is a Network Diagram? Chap 6 A D C G E H F B Network Diagram A visual flow diagram of the sequences, interrelationships and dependencies of all the all the activities necessary to complete the project. An activity is an element of the project that consumes time. More than one WBS work plan can be included in an activity. Networks provide the project schedule by identifying the dependencies, sequencing and timing of the activities. Activity time is derived from the task times in the work packages. Ask the three questions

Network Terminology Chap 6 Activity – An element of the project that requires time. Merge Activity – an activity that has more than one activity immediately preceding it. Parallel Activities – Activities that can take place at the same time. Path – A sequence of connected dependent activities Critical Path – The path with the longest duration through the network. Any increase of time to the CP will result in a equal increase in the project. Event – A point in time when an activity is started or completed. It does not consume time Burst Activity – An activity that has more than one activity immediately following it.

Basic Rules to Follow Networks flow from left to right Chap 6 Networks flow from left to right An activity cannot begin until all preceding connected have been completed. Arrows on networks indicate precedence and flow Each activity should have a unique id number An activity ID number must be larger that of any preceding activities Looping or recycling thru a set of activities are not allowed. Conditional statements are not allowed. Use a common start and end when you have multiple starts and or projects.

Deterministic Time Estimates Chap 6 Steps 1. Calculate the length of each path 2. Determine the critical path 3. Determine the expected length of the project 4. Define slack time for each activity Compute ES, LS, EF, LF for each activity Algorithms Early Start (ES): Early Finish (EF): ES + t Late Start (LS): LF - t Late Finish (LF): Slack (SL): LS - ES or LF - EF

Example - Deterministic Chap 6 Activity Description Time Precedence A Prepare BOM 1 - B Prep assembly charts 3 A C Order & await delivery of materials 7 A D Organize production line 2 B E Specify inspection procedures 1 B F Setup inspection stations 2 D,E G Train workers 3 D H Assemble product 7 C,F,G Find ES, EF, LS, LF, Slack, CP and project duration.

Deterministic Precedent Diagram Chap 6 A C B E D F G H

Probabilistic When the task time to complete varies. Chap 6 When the task time to complete varies. Uses a BETA distribution to evaluate Uses estimates of: Most optimistic (a) Most likely (m) Most pessimistic (b) Algorithms: Expected event time to complete: te = (a + 4m + b) / 6 Variance (2e): = (b - a)2 / 36 Expected path time to complete: t path =  t e Path Variance(path): =  2e

Probabilistic Example Chap 6 Activity Description a b m Precedence A Prepare BOM 0.6 1.8 0.9 - B Prep assembly charts 2.0 4.0 3.0 A C Order & await delivery of materials 5.0 9.0 7.0 A D Organize production line 1.2 3.6 1.8 B E Specify inspection procedures 0.7 1.3 1.0 B F Setup inspection stations 1.0 5.0 1.5 D,E G Train workers 2.0 3.6 3.1 D H Assemble product 6.0 8.0 7.0 C,F,G Find: te , e, t path , path, ES, LS, LF, EF, SLACK, CP Finding ES, LS, LF, EF & Slack is the same as deterministic. Finding the probability that project will complete in time t Algorithm: Z = (t - t cp ) / cp Find P(Z) using normal distribution table. Probability that the project will not be completed is 1 - P(Z)

Probabilistic Precedent Diagram Chap 6 A B E D F G H C Z = t – tcp / cp Z = 16 – 16/.7 Z = 0 P(Z) = .5 Z = 17 – 16)/.7 = 1.42 P(Z) = .992 cp = ( )0.5 = (.04+.11+.16+.07+.11)0.5 = .70

Advanced Network Techniques Chap 6 Laddering Laddering is used when it is not necessary for a task to be completely finished before the next activity is started. Trench 1/3 Trench 1/3 Trench 1/3 Pipe 1/3 Pipe 1/3 Pipe 1/3 Refill 1/3 Refill 1/3 Refill 1/3 Use of Lags Represents the minimal amount of time before the next task can begin. Can be used to represent wait times Can be used to constrain the start and finish of an activity Make sure lag is not used as a “slush” factor to reduce risk Lag 12 hrs Paint Box Finish – to- Start

Activity Relationships Chap 6 Start – To – Start (SS) Primarily used when activities can be performed simultaneously Can be used to compress the project by changing finish –to- start relationships by using start – to – start with lags Can be used in cases of laddering Trench Pipe Refill Lag 3 hrs Finish – to –Finish (FF) The finish of one depends on the finish of another. An example is documentation of the other activity (i.e. testing, design, minutes of a meeting) Start – to – Finish (SF) One activity will continue until another event starts.

Hammock Activities An activity that spans over a segment of a project. Chap 6 An activity that spans over a segment of a project. The activity duration is determined after the network plan is drawn. Used to identify the use of fixed resources or costs over a project segment. The duration is determined from the early start of the initial activity of the segment to the early finish of the last activity. The hammock activity does not add to the project time but parallels one or more activities. copy machine movie camera quality control Useful for assigning and controlling indirect costs

Project Plan Example Boulangerie Fashion Show European Restaurant Chap 4 Boulangerie Fashion Show European Restaurant

Chap 6 Questions