chapter-1.pptx scheduling for construction

Engineering reference

1. Course: Construction Planning & Scheduling Instructor: KARTHIKEYAN KUMARASAMY Chapter-1

2. Chapter-one 1. Project planning 1.1 definitions of project, planning, scheduling, project planning and construction project; What is project? Project is a temporary endeavor undertaken to create a unique product , service, or result. Projects have scopes , schedules , and costs and are accomplished within specific deadlines , budgets , and according to specification Why temporary? Temporary does not mean short in duration Every project has a definite beginning and a definite end

3. When does a project comes to an end? Project's objectives are achieved/become clear that objectives can not be met Purpose of the project is to attain its objective and then terminate Why a project is a unique product/service/result ? Uniqueness is an important characteristics of project deliverables. Example – Mass housing Presence of repetitive elements does not change the fundamental uniqueness of the project work

4. What is planning? Planning is the most important phase of project management. Planning aims at formulation of a time based plan of action for coordinating various activities and resources to achieve specified objectives. Planning is the process of developing the project plan. Planning is important because; It provides directions, It provides unifying framework, It helps to reveal future opportunities and treats, It provides performance standards

5. What are the objectives of planning ? Proper design of each element of the project Proper selection of equipment and machinery in big projects, the use of large capacity plants are found economical Procurement of materials well in advance Proper arrangement of repair of equipment and machinery Employment of trained and experienced staff on the project To provide incentive for good workers To arrange constant flow of funds for the completion of project To provide proper safety measures and ventilation, proper arrangement of light and water .

6. 1.2 Steps in the planning process The planning process consists of the following basic tasks; Define the technical approach used to solve the problem. Define and sequence the tasks to be performed and identify all deliverables associated with the project. Define the dependency relations between tasks. Estimate the resources required to perform each tasks. Schedule all tasks to be performed. Define a budget to performing the tasks. Define the organization used to execute the project. Identify the know risks in executing the project. Define the process used for ensuring quality. Define the process used for specifying and controlling requirements.

7. What is scheduling? Schedulin g is the determination of the timing and sequence of operations in the project and their assembly to give the overall completion time . Scheduling is an application of special knowledge or judgment of the mathematical, physical, or engineering sciences to the conception or implementation of creative work. Scheduling is a discipline that is performed by every person, every day .

8. What is project planning? project planning is defines the project activities and end products that will be performed and describes how the activities will be accomplished. The purpose of project planning is to define each major task, estimate the time and resources required , and provide a framework for management review control. Project planning answers the questions ; What is going to be done? How ? Where ? By whom ? And When (in general terms, the project’s start and end)? Scheduling deals with when on a detailed level.

9. The project planning activities and goals include defining: T he specific work to be performed and goals that define and bind the project. Estimates to be documented for planning, tracking and controlling the project. Commitments that are planned, documented and agreed to by affect groups. Project alternatives, assumptions and constraints

10. 1.3 Project planning steps; Select the project. Identify project scope and objectives. Identify project infrastructures. Analyze project characteristics. Identify project products and activities. Estimate effort for each activities. Identify activity risks. Allocate resources. Review/publicize plan. Execute plan.

11. What is construction project?

12. Residential Commercial Infrastructure and heavy construction Industrial Major differences exist: In the way the projects are funded, In the technologies involved, And in the manner in which the designers, builders, and owners interact.

13. 1.4 Tools of project planning Much of the technical content of a project plans are derived from the basic tools include; Work break down structure (WBS) and work packages- used to define the project work and break it down into specific tasks. Responsibility matrix- used to define project organization, key individuals and their responsibilities. Events and Milestones- used to identify critical points and major occurrences on the project schedule. Gantt charts- used to display the project master schedule and detailed task schedules. Additional project planning tools such as; networks, critical path analysis, PERT/GERT, cost estimating, budgeting and forecasting .

14. Work Breakdown structure It is a foundation of project planning. It is a method of breaking down a project into individual elements/activities/tasks in a hierarchical structure which can be scheduled. It defines tasks that can be completed independently of other tasks, facilitating resource allocation, assignment of responsibilities and measurement and control of the project. It is developed before estimation of activity durations.

15. Project activities: Activity: A task or a certain amount of work to be done in the project Requires time to complete Usually represented by an arrow in a network diagram Event: Signals the beginning or ending of an activity Designates a point in time Usually represented by a circle (node) in a network diagram Network: Shows the sequential relationships among activities using nodes and arrows.

16. Network Diagrams: Network diagram refers to a graphical representation of the tasks/activities necessary to complete a project. Network visualizes the flow of tasks & their relationships. In network diagram, : each task labeled with an identifier (usually by a letter) Task duration expressed in standard unit like days time goes from left to right Two classic formats in network diagram: AOA : Activity on Arrow AON : Activity on Node

17. Activity on Arrow (AOA): Task/Activity is represented by an arrow bounded on either end by a Node (Event). Events are represented by Nodes which are circles. Each Event is identified by a Number. The Activity is designated by a letter ( A, B, C, etc.) or by the leading event number and the following event number - i.e. Activity 1–2.

18. Example 1 : AOA Network for House Construction Project

19. Activity on Node (AON): Task is represented by Node as the completion of an activity. Arrows represent the sequential linkages between activities. For example, Node 1 is Complete Task 1, Node 2 is Complete Task 2.

20. Example 2 : AON Network for House Construction Project

21. Activity Relationships - AOA

22. Dummy Activities;

23. Constructing Network Diagrams

24. Activity Description Pre-requisites A Erection of the site work _ B Fence site _ C Bend reinforcement A D Dig foundation B E Fabricate steel works A,C F Install concrete plant B G Place reinforcement C,D H Concrete foundation G,F I Paint steel work E J Erect steel work H,I K Give finishing touch J Problem 1;

25. Problem 2; job Imm. predecessor A _ B _ C _ D A,B E A,B,C F A,B,C G C H D,E I D,E,F J G,H,I Problem 3; If there are five activities P, Q, R, S and T such that P, Q, R have no immediate predecessors but S and T have immediate predecessors P, Q and Q, R respectively. Represent this situation by a network .

26. 1.5 Estimating activity duration and direct cost Duration of an activity is defined as the expected economical transaction time. The estimation of time is based upon the current practices carried out in an organized manner under the normal prevailing conditions, and its assessment is done preferably, by the person responsible for its performance. Duration estimation is based on current practices. This implies that the estimation is based on the present knowledge of the method of transaction in an economical way; it may undergo a change with the passage of time or with improved techniques. Under normal prevailing site condition using economical resource

27. Cont’d……… Activity is Performed in an organized manner  breaking down activity into elements, matching optimum resource for each elements, laying down a systematic way method of execution, specifying objectives and assigning responsibility . Responsible person  this makes the duration estimate realistic and meaningful. The construction activity accomplishment process combines resources: manpower, materials, and machinery. the first step in duration estimation is the methodology to be used for transforming these input resources into the desired activity.

28. Duration Estimation methods: 1 . One time estimate: the estimation of duration is based on one of the following; Planning data Past experience or execution of a similar project Average time assessed by a group of executives. 2. Three time estimate: When the exact duration of an activity, like research and development, is not certain, the three-times estimate is used to compute its expected duration.

29. Cont’d…… Application in Construction Projects Planning of the projects especially, at the feasibility stage The Skelton networks enclosed with the tender documents. The contracted works, where time is the main consideration for management The complex structures, where the exact duration estimate is difficult to assess. 3. Trapezoidal distribution estimate (Reading assignment)

30. Duration Estimation procedure Estimating the quantity of work. Deciding the labor and material constants. Assessing the effective activity-wise employment of resource. Estimate the activity completion period. Completion period = Quantity of work/[output per unit of resource x resource earmarked] t=Q/( nXp )