Planning for Construction
The following aspects shall be considered:
a) Sequencing of project components,
b) Planning tools:
I) Work breakdown structures (WBS),
2) Bar charts, and
3) Network techniques and scheduling.
c) Resource planning , and
d) Time cost trade-off.
5.1.2.1 Sequencing of project components
Methodology of construction shall be detailed before the start of the project. Sequencing of project
components shall be done on the basis of methodology adopted and availability of resources. This shall be
reviewed during the progress of the project and revised, if necessary.
5.1.2.2 Planning tools
The planning tools describ ed below may be employed for effective management of a construction project:
a) Work Breakdown Structure (WBS) - The WBS shall identify the total scope of works involved in the project and shall form the basis schedule. Through WBS, the project shall be sub-divided into major sub-divisions (work packages) and each major sub-division shall be further sub-divided into additional levels as required up to the level of activities that could form the basis for monitoring and control of project performance in terms of time, cost and quality parameters. WBS shall provide activity listing with associated cost account codes for the preparation of project schedule either by bar charts or by network
diagramming methods.
b) Bar Chart - Bar chart is the simplest form of project scheduling and used for small and complex projects and in preliminary planning and tender stages of major projects. A typical bar chart form of project schedule depicts the various activities on a calendar time scale in the form of bars in their relative positions with start and finish dates and length of bar indicating probable activity duration. Linked bars represent the interdependencies between the activities. Bar chart type of schedule shall be used to comprehend, summarize and display the results of complex project network analysis and further monitoring and controlling process.
c) Network Techniques and Scheduling
1) Network Diagramming Methods Network based project schedule shall be used for major and complex projects. In
this method, the network of project activities identified through WBS is developed incorporating their logical
relationships and interdependencies.The two available approaches for network diagramming techniques are Arrow
Diagramming Method (ADM) and Precedence Diagramming Method (PDM).
2) Network Analysis and Scheduling - The project network incorporating the activity durations and logical relationships shall
be analyzed with forward and backward pass schedule calculations to establish early and late start and finish time of
activities with their available floats, critical activities, critical path and overall project duration. The project schedule is
prepared in terms of calendar dates of start and finish of activities with available floats. The network schedule shall also
be presented in the fonn of linked bar chart or in tabular fonnat.
For details on network preparation and analysis, reference shall be made to IS 14580 (Part 1) and IS 14580 (Part 2). Network schedule shall be prepared for all disciplines and they shall be integrated into a Master Control Schedule.
5.1.2.3 Resource planning
This shall involve the following:
a) Resource Allocation - The feasibility of the network shall be checked with respect to manpower, equipment, other resources required at the site.
b) Resource Levelling - It shall be done by reallocating the slack resources from non-critical path to critical path activity in order to obtain a reduction of time or by shifting the activities within the floats available with them, to obtain an optimum uniform resource requirements.
c) Resource Schedule - Schedule of following resource requirements with respect to time shall be prepared on the basis of network developed and kept in the database for project control purposes:
I) Technology,
2) Manpower:
i) Technical staff,
ii) Skilled labour, and
iii) Unskilled labour,
3) Machinery,
4) Materials, and
5) Cash flow.
Resource schedule shall be prepared separately for client, consultant and
construction agency.
5.1.2.4 Time cost trade-off
Time cost trade-off analysis shall be done to obtain a minimum total cost of the project within the specified time. This shall bedone taking into consideration direct cost and indirect cost of the project.
5.1.3 Tender Action
5.1.3.1 Preparation of tender documents The bill of quantities, specifications, drawings and conditions of contract should be prepared on the basis of design and details finalized in project proposal development stage (see 5.1.1) keeping in view the construction project delivery model selected. The format, terminologies and terms and conditions should be as per the standard engineering practices. In case of any special item or condition, the same shall be described clearly to avoid any ambiguity.
Selection of construction agency shall be done by either:
a) Open Competitive Bidding - In this case, tender notice should be publicized adequately to obtain competitive tenders from competent agencies for the project ; or b) Limited Competitive Bidding - In large, specialized and important works,
pre-qualification of contractors shall be done considering their financial capability, bid capacity, experience of similar type of works, past performance; technical staff; and plants and machinery available.
5.1.3.3 Bid evaluation. negotiation and award ofwork After due evaluation and negotiation. with the bidders.
if required, the work shall be awarded to the construction agency based on competitive technical and
financial bids.