Construction Project Planning and Scheduling PDF

Construction Project Planning and Scheduling Introduction  Planning is the first step of our total project management philosophy for planning, organizing, leading and controlling the execution of capital projects. Introduction  Without planning, it is difficult to envisage the...

Construction Project Planning and Scheduling Introduction  Planning is the first step of our total project management philosophy for planning, organizing, leading and controlling the execution of capital projects. Introduction  Without planning, it is difficult to envisage the successful conclusion of any project or the effective control of time, money or resources. Introduction  Planning is also essential in order to deal with construction risks and devise safe working methods.  Introduction “If you fail to plan, you are planning to fail.” Benjamin Franklin  Reasons for Planning  To set a realistic time framework for the project  To establish realistic standards and avoid ‘wishful thinking’  To aid control during the project  To monitor performance in terms of output, time and money  To review progress and take action when necessary to correct the situation  KINDS OF PLANNING KINDS OF PLANNING Organizational level Focus Time period Corporate range Strategic Long Divisional Operational Medium range Functional Tactic Short range  ORGANIZATIONAL PLANNING ❑ Corporate planning or top level planning: It lays down the objectives, policies and strategies of an organization. Usually made for a longer time period. ❑ Divisional planning or middle level planning: It is related to a particular department or division. It lays down the objectives, policies and strategies of a department. ❑ Sectional planning or lower level planning: focused on laying down detail plans for the day to day guidance.  FOCUSED PLANNING ❑ Strategic planning: deciding the objectives and to decide the resource marshalling in order to realize the objectives. Done by the top management. ❑ Operational planning: ensuring efficient use of resources and to develop a control mechanism so as maximum efficiency is ensured. ❑ Tactical planning: made for short term moves. Required to meet the sudden changes in the environment forces.  TIME PERIOD PLANNING ❑ Long range planning: for a period of five years at least. Involves capital budgeting, product planning, project planning etc. deals with a great uncertainty. ❑ Medium range: for one to five years. Relate to development of new products and markets, product publicity etc. supportive to long range plans. ❑ Short range: up to one year. Made to achieve short term goals. Focused on the internal environment of the business.  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Getting a feel for the project Establishing key project dates Establishing key activities or events Assessing how long the activities will take Establishing the sequence Deciding which programming technique to use 11  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Getting a feel for the project Study the drawings and project documentation Visit the site Assess the scale and scope of the project Assess the approximate value of the project Consider the rate of expenditure 12  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Establishing key project dates Project start and finishes dates Sectional or phased completion dates Holiday periods Commissioning or handover 13  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Establishing key activities or events Checklist of the key activities/events during the design stage Brief the design team Make professional appointments Apply for building regulation approval Pre-qualify contractors Appointment contractors 14  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Establishing key activities or events Checklist of the key activities/events during the tender stage Prepare tender documents Complete the pre-construction H and S information Period for tendering Evaluate tenders Compile contract documentation 15  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Establishing key activities or events Checklist of the key activities/events during the pre- contract stage Appoint project staff Develop the construction phase H and S plan Prepare requirement schedules Pre-start meeting Permit start of construction work 16  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Establishing key activities or events Checklist of the key activities/events during the construction stage MEPF Set up site establishment Finishes Groundworks or substructure External works and Frame/external envelope drainage Floors Practical or substantial Roof structure and cladding completion 17 Building Watertight Clear site  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Assessing how long the activities will take 18  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Establishing the sequence 19  Planning a Project  The planning of a project requires a logical approach involving various steps or thought processes: Deciding which programming technique to use 20  Programming Techniques  A project is a collection of tasks that must be completed in minimum time or at minimal cost.  Objectives of Project Scheduling ◼ Completing the project as early as possible by determining the earliest start and finish of each activity. ◼ Calculating the likelihood a project will be completed within a certain time period. ◼ Finding the minimum cost schedule needed to complete the project by a certain date. 21  Programming Techniques  Objectives of Project Scheduling – Investigating the results of possible delays in activity’s completion time. – Progress control. – Smoothing out resource allocation over the duration of the project. 22 Steps in the Planning Process 1) Identify the tasks. 2) Clearly state the objective of each task. 3) Estimate the Personnel, Time and Resources to meet objectives. 4) Develop a task sequence. 5) Estimate the work item development costs.  Steps in the Planning Process 1) Identify the tasks. Tasks bring the project from a problem to a product. Initially activities to be performed Start with major development activities Break down into smaller tasks 2) Clearly state the objective of each task. Tasks refined to where results of the activities are stated objectives. Easily understood by entire design team Specific as to what info is to be developed Feasible Given time, personnel, equipment  Steps in the Planning Process 3) Estimate the Personnel, Time and Resources to meet objectives. ▪ Estimates are always difficult as design takes time. ▪ A variety of schemes are used to estimate, all are based on assumptions. Track record within companies is always the best indicator.  Steps in the Planning Process 4) Develop a task sequence. Sequential Tasks Parallel tasks ▪ Coupled ▪ Uncoupled ▪ Develop a planning/scheduling chart ▪ milestone or Gantt chart ▪ PERT  Steps in the Planning Process 4) Develop a task sequence. Design Structure Matrix (Shows Dependency of tasks) A B C D E F G Mobilization A A Layouting and Staking B X B Excavation of Column Footing C X C Fabricate Footing & Column Rebars D X D Fabricate Column Forms E X E Install Column & Footing Rebars F X X F Concreting of Column Footing G X G 5) Estimate the product development costs.  Planning and Scheduling Gantt Chart ◼ The bar or Gantt Chart is a widely used simple project scheduling technique. ◼ Advantages include:  Direct correlation with time.  Straight forward relationship with projects involving a limited number of tasks.  Straight forward integration of subtasks having separate scheduling charts.  Time schedule is flexible and is expanded to show tasks of shorter nature.  Progress against the plan is easily reflected. ◼ Disadvantage includes:  That it does not convey the complex interrelationships that may occur between tasks. Gantt Chart  Planning and Scheduling Milestone Chart ◼ A Milestone chart is similar to a Gantt Chart with the emphasis placed on task completion. ◼ It embodies the same simplified techniques as does the Gantt chart. It does not portray the interrelationships between tasks and hence does not identify the critical path. Milestone Chart  Planning and Scheduling PE RT {Program Evaluation and Review Technique} ◼ The PERT chart has distinct advantages for complex projects with interrelated tasks. ◼ PERT, due to its complexity of time estimations, has given way to more popular CPM methods.  Planning and Scheduling  PERT Chart ◼ Three Time Estimates:  OPTIMISTIC - Shortest time; to  MOST LIKELY - Best Estimate; tM  PESSIMISTIC - Longest time; tp  Planning and Scheduling Critical Path Method ◼ Has some common characteristics with PERT  Defined by activities and events ◼ An activity is a time-consuming effort that is required to complete part of a project. Shown as an arrow on the diagram ◼ An event is denoted by a circle and defines the end of one activity and beginning of the next. An event may be a decision point. Activity Event  DEFINITION OF TERMS IN A NETWORK  Activity : any portions of project (tasks) which required by project, uses up resource and consumes time – may involve labor, paper work, contractual negotiations, machinery operations Activity on Arrow (AOA) showed as arrow, AON – Activity on Node  Event : beginning or ending points of one or more activities, instantaneous point in time, also called ‘nodes’  Network : Combination of all project activities and the events PRECEEDING SUCCESSOR A B ACTIVITY C ES LS D EF LF D ES LS EVENT  Planning and Scheduling Critical Path Method ◼ Terminology  Earliest Start time (ES)  Latest Start time (LS)  Earliest Finish time (EF),  Duration (D)  EF = ES + D  Latest Finish (LF) LF = LS + D  Total Float (TF) TF = LS - ES ◼ (Slack between the earliest and latest start times) ◼ On CP, the total float is zero.  Critical Path Method CPM Example  Critical Path Method ACTIVITY ACTIVITY PREDECESSOR DURATION NO. Earliest Start Times Establis hed 1 Mobilization 1 day 2 Layout and Staking 1 day 1 3 Excavate Footing 4 days 2 4 Fabricate Footing rebar 2 days 1 5 Fabricate Column Rebar 3 days 4 6 Install Footing Rebars 1 day 3,4 7 Install Column Rebars 4 days 6,5 8 Concreting of Footing 1 day 7 9 Fabricate Column Forms 5 days 2 10 Install Column Forms 2 days 9,8 11 Concreting of Column 2 days 10  Critical Path Method NETWORK DIAGRAM INST COL FORM FAB FORM 9 10 COL CONC COL INST INST CONC EXC FTNG COL MOB FTNG L&S FTNG REB REB 1 2 4 5 7 8 11 FAB FTNG REB 3 6 FAB COL. REB  CPM Calculations The calculations of the critical path and the project duration is relatively simple, requiring only addition and subtraction. Forward Pass The first step in the calculations is to perform a forward pass. In this step, the early start and early finish of each activity are calculated. The early start (ES) is the earliest time as activity may start. The early finish (EF) is the earliest point at which an activity can be completed. EF = ES + D  CPM Calculations Backward Pass The second stage is to move backward through the network and determine the late finish and late start times of each activity. The late finish (LF) for the activity in the network is assumed to be equal to the early finish calculated in the forward pass. If there are multiple closing activities, the greatest early finish is used. All other nodes are calculated using: LF = Minimum LS of all following activities Then the late start (LS) can be calculated as: LS = LF - D  CPM Calculations CPM Float Critical activities cannot be delayed or else the duration of the project will be longer. Activities with equal ES and EF or zero float are considered critical activities and belongs to the critical path. Those activities that are not critical path will have scheduling leeway, meaning that their start times can be adjusted within limits that will not affect the duration of the project. In construction industry, this scheduling leeway is commonly called as total float.  CPM Calculations TOTAL FLOAT TF = LF – EF = LS – ES FREE FLOAT: Free float is the minimum early start of all the following activities less the early finish FF = ESMIN – (ES + DURATION)  DATA SHEET: START FINISH FLOAT CRITICA ACTIVI PREDESES DURA L TY SOR TION ACTIVIT ES LS EF LF TF FF Y A - 2 B A 3 C B 4 D A,B 2 E C 3 F D 1  BUILDING CONSTRUCTION METHODOLOGY ( BY PERT/CPM DIAGRAM) PROJECT: ONE(1) STOREY ONE (1) CLASSROOM SCHOOL BUILDING DURATION: 30 CALENDAR DAYS PROC UREMENT/D ELIVERY OF CONSTRUC TION MATER IA LS C 26 26 28 ELECTR IC AL /SA NITA RY ROUGH-IN H INST. EL EC T/ 23 25 MECH/SANITAR Y 14 FIX TUR ES CA RPENTRY W ORKS U P 1 23 25 29 30 EAR TH 2 MOVE MOVE- W ORKS MASONRY IN CONC RETE PAINTING OUT W ORKS A E W ORKS K ROOF FRAMING M ROOF ING O FINISHES S T V B G 0 0 2 2 44 5 9 9 12 12 5 17 17 4 21 21 4 25 25 28 28 2 30 30 2 2 3 3 WA IT WA IT WA IT WA IT WA IT D F L 2 N Q R 2 3 47 2 1215 17 19 2 21 24 4 25 28 WA IT SOIL 1 BACKFILL INST. OF PURL INS INST. GUTTER & INST. FA B. MATL S & POISONING FL USHING HAR DW AR E I J 9 18 3 12 21 DA MPROOFING/SLA B ON FILL 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 CA LENDA R DA YS LEGEND: NETWORK - A B ES LS EF LF ACTIVITY - EVENT - A ES LS DUMMY - CRITICA L PATH -