CONSTRUCTION MANAGEMENT CHAPTER 3 PLANNING

CONSTRUCTION MANAGEMENT CHAPTER 3 PLANNING

Planning of Works Contract Form of contract by which one party undertakes to the other to perform certain work, for a price. Corresponds to the execution of a set of. Construction site - Where you perform the work, and the place where direct support to the work activities are developed. Owner - Person, individual or collective, who is executing a work, directly or through intermediaries to whom belong the goods and company. Technical Director - Technical appointed by the contractor, responsible for directing and executing the works. It is the technician responsible for the flawless execution of construction and the inherent security problems. Terminology and Definitions 2

Planning of Works Project manager - Person, individual or collective, responsible for project management (economy, architecture, engineering). Designer company, technical or technical group engaging with the developer project planning. Fiscalization The main function of fiscalization is in direct action to prevent and participation in the production process, effort to control the quality, price and term. In public works, monitor the implementation of the work is carried out by a supervisor or developer. representative of the developer " designated by the Terminology and Definitions 3

What's the purpose of planning? get the best relationship between the three factors: Duration / Resource Units / Work Duration Resources Work which aims at planning 4

What's the meaning of planning? Planning, aims to define the best way to accomplish the project by adressing questions such as: Which tasks have to be perfomed? Activities to complet the project Which constructions processes to use? Methods and techniques appropriate What means are necessary? Resources involved When perfoming the tasks? Sequence and timing which aims at plannig 5

Kinds of Planning 6

Kinds of Planning Strategic Planning: identifies efforts that managers should do for the company to achieve its objectives; defines objectives and long-term policies for the organization and how to achieve them is prepared by the administration. They only have the big objectives is characterized by high uncertainty. The information has no detaill Strategic Planning 7

Kinds of Planning Coordination Planning : articulates the company's various operating units according to the objectives set by management. It is made on the basis of implementation of project; refers to the medium-term objectives; is less rigid and has less risk and uncertainty associated; - the data for this planning could be the execution project. Planning Coordination 8

Kinds of Planning Operacional Planning: identify the resources needed for the project and key dates, promotes the development of work programs; is on the short term and more flexible; determines specific tasks within the prescribed period and with the resources available; is prepared by the organization of the production level, Technical director Operacional Planning 9

Graphical Representation of Planning Bar Chart or (Gantt chart) Activity-on-Arrow Network An activity: Is a task consuming resources and time. An event: Is the start and/or the finish of an activity or group of activities. 10

Project of a new product Bar Chart or Gantt Chart 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 26 A B C D E F G H I J K L M

Graphical Representation of Planning Bar chart or Gantt Chart Project of a new product Horizontal Bars: C time scale ( Duration) Caracterização das tarefas Arrows: Interdependence ID: WBSde sequência da actividade Critical Activities/ Activities with FLOAT Exemplos de Representação Gráfica do Planeamento 12

Conventions on A0A network -Time flows from left to right - Head modes, (or event) always have a number higher than that of the tail mode. Identification of Activities EET i A j Node label LET The mode at the beginning of na activity is known as a tail or preceding mode (i), while that at the conclusion of na activity is known as a head or succeeding mode. Activity (A) has a name and a duration. 13 13

14 Conventions on A0A network Basically, the representation of events and activities is governed by one, simple dependency rule which requires that an activity depends upon another activity to emerge from the head of the activity which it depends. A 3 4 This dependency rule gives rise to two fundamental properties of events and activities: B C 5 6

Conventions on A0A network 15 - An event cannot be said to be realized (or be reached ) until all activities leading in it are complete. For example, is found that event 4 can only be said to occur when activity 3-4 are complete. - No activity can start until its tail event is realized this activities 4 5 and 4-6 cannot start until event 4 is realized. Note: Unless otherwise specified, all the start events can occur at the start of the project and all finish events will occur at the end of the project.

16 Dummy Activities Dummy activities, do not require resources but may in some cases take time. They are drawn as broken or dotted arrows. Tree types: 3 - - - - - - - 5 Identity dummies; Logic dummies Transit time dummies Consider the situation: Activity K depends on activity A; Activity L depends on activities A and B A 6 B L K

- - - 17 Dummy Activities For activity L is, quite corretly however for activity K it is not right, as it depends only as activity A. solution A 6 K Example: B A - -- - - - - - 3 3 3 L K L B 3 M

PLANEAMENTO E GESTÃO DA CONSTRUÇÃO Activities / Tasks Time in delay: lag time ou lead time The delay time can be: positive or negative FS + LAG FS - LEAD Tempo de atraso 18

19 Analising The Critical Path The total project time (TPT) is the shortest time in which the project can be complete. A node has two times associated with it, one, from the forward pass, ist earliest event time (EET), the other from, the backward pass, its latest event time (LET), the latest event time by whitch the event must be realized if the total project time is to be achieved. Event (node) representation: EET = EST Node label LET = LFT

Analising The Critical Path The total project time (TPT) is the shortest time in which the project can be completed, and this is determined by a sequence of activities known as the critical path. For the calculation: (EFT) Earliest Finishing Time = Earliest Start Time (EST) + duration The critical path is then identified by carrying out a backward pass whereby the latest finishing time (LFT) of an activity and its associated latest starting time (LST) are calculated, given by: LST = LFT - duration 20

Analising The Critical Path Consider a part diagram where node 9 has three entering activities K, L, M and the forward pass shows that: 1 10 K - 16 Forward pass 5 20 L - 17 9 48 A 7 30 M - 18 21

22 Analising The Critical Path Activity K, duration 16 weeks, tail-node 01 has an EET of 10 weeks. Activities L (EST=20) and M (EST=30) Activity M has an EST of 30 weeks and hence an LFT of (30 +18) weeks = 48 weeks. Activities K and L The earliest time at which all activities entering event 9 are complete is week 48, so that the EET for event 9 is week 48 and the EST for all activities emerging directly from event 9 is week 48.

23 Analising The Critical Path In reverse, consider a part-diagram where node 02 has three emerging activities, W, X, Y, and the backward pass shows that: W - 19 4 85 P 2 40 X - 20 6 60 Backward pass Y - 21 8 72

24 Analising The Critical Path Activity W, duration 19 weeks, has a lead node 4 with a LET of 85 weeks. Activities X and Y Then, Activity X has a LFT of 60 weeks and a LST of (60-20) = 40 weeks Activities W and y The latest time by which event 02 must be realized is the earliest of the LST of all emerging activities, that is week 40 so that the LET for the event 2 is week 40.

25 Analising The Critical Path EST LST Calculation in Detail: EFT LFT EFT = máx (EST +dur) A-16 J-15 2 16 E-10 1 0 B-20 20 D-15 G-3 K-12 3 7 35 8 38 9 51 C-30 H-16

26 Analising The Critical Path EST = EET LFT = LET Here node 9 has a LET equal to TPT just calculated, 51 weeks. Then: Node 8 has a LET of (51 12) weeks = 39 weeks, that is, activities J, E and G may finish at the end of week 39. Node 2 has a LET of (39-15) weeks = 24 weeks, that is, activity A may finish at the end of week 24. When a node has several activities emerging from it, then its LET is determined by the earliest of the LST of the emerging activities.

27 Analising The Critical Path Node 3 has two activities (E and D) emerging from it: LST for activity E is (39-10) weeks = 29 weeks LST for activity D is (35-15) weeks = 20 weeks Hence Node 3 has na LET of 20 weeks, that is, activity B may finish at week 20 Since node 1 is the first node LST of the whole project is node 0. The EET and LET are equal. Consider activity D 3 20 20 D 15 7 35 35

28 Analising The Critical Path Calculation in Detail: LST = min (LFT durt) A-16 2 16 J-15 24 E-10 1 0 0 B-20 20 D-15 G-3 K-12 3 7 35 8 38 9 51 20 35 39 51 C-30 H-16

Analising The Critical Path Latest Finish Time = 35 Earliest Starting Time = 20 Time Available in weeks = 15 Time required in Weeks = 15 Spare Time = 0 Thus, there is no spare time in activity D, if it starts late or the duration increases by any amount, the TPT will be increased. As with any dimension affecting total perfomance activity D is said to be critical. The critical path is a chain of activities that is critical 29

Analising The Critical Path Activity C LFT = 51 EST = 0 It is activity C critical? Three factors characterize the critical path: 1. It starts at the first node; 2. It is continuous; 3. It ends at the last node. 30

Total Float The earliest tail and the latest head event times form boundaries within which activities are able to move. Looking again activity J: EST = 16 LFT = 39 Maximum available time = 39-16 = 23 weeks EST 2 16 24 J 15 LST 8 38 39 K 12 Necessary time = 15 weeks 31

Total Float, Free Float and Independent Float 32 Thus, the activity can be extended or delayed by (23-15) = 8 weeks. Any expansion or delay greater than this increase the overall project time. This time of 8 weeks is known as the Total Float Total Float = LFT EST Duration; Free Float = EFT EST Duration; F.F: the total amount by which an activity can be extended or delayed without affecting succeeding activities or the TPT Independent Float = EFT LST Duration; I.F: the total amount by which na activity can be extended or delayed without affecting preceding or succeeding activities or increasing the TPT

Exerc. To draw the AOA and AON Network Activities Precedences Duraction (week) A - 6 B A 4 C B 7 D A 2 E D 4 F E 10 G - 2 H G 10 I - 13 J H ; I 6 K A 9 L C ; K 3 M J ; L 5

Project of a new product Table of activities Actividades Description ( Name, Duration e Precedences ;(Yes) Custs and Resources (No) Type of precedences Finish/Start (F.S.) Durations Durations with fixed value

Diagram of Gantt Project of a new product Bars: Length proportional to the duration 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 A B C D E F G H I J K L M