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8. A DVANCED R ESOURCE M ANAGEMENT. Objective: To develop new perspectives of space as resources, that will enable it to be more readily integrated with other variables into a project plan . Summary: 8.1 Introduction 8.2 Planning for Space as a Resource. 8.1 I NTRODUCTION.
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8. ADVANCED RESOURCE MANAGEMENT Objective: To develop new perspectives of space as resources, that will enable it to be more readily integrated with other variables into a project plan . Summary: 8.1 Introduction 8.2 Planning for Space as a Resource
8.1 INTRODUCTION A primary objective of planning is to arrive at a schedule for work that satisfies all objectives, and meets all constraints: • It is relatively easy to plan a project to satisfy any one objective, or any one constraint; • Planning to satisfy many objectives and constraints is much harder; • We try to develop planning tools that will enable us to satisfy all such requirements, for example, computer-based CPM enables us to develop a plan that: • satisfies all logical constraints (the activity dependencies); • satisfies all the productive resource availability constraints (through multiple resource leveling); • suggests ways of meeting time deadlines (by identifying the critical activities that need crashing);
If an objective or constraint cannot be integrated with the other objectives or constraints within a single analysis, then: • it will have to be treated independently; • this may result in a compromise whereby: • the objective or constraint is not properly satisfied; or • the other objectives and constraints will no longer be satisfied. • Two factors that have not been effectively integrated in this way are: • space; and • costs. • Computer-based CPM does allow for cost analysis, but: • traditionally this has not been done in a way that allows it to be optimized in an integrated way with the other objectives and constraints. • We can overcome this problem by treating space and costs in the same way as the productive resources: • however, this is not as straight forward as for the productive resources (such as equipment and labor).
8.2 PLANNINGFOR SPACEASA RESOURCE Uses of space : • storage (materials, equipment, etc): • short term (temp storage of blocks while waiting to be stacked on an elevator); • long term (storage of aggregate at a concrete batching plant); • performing activities: • access ways (eg: a haul road); • fixed location operating spaces eg: (to locate a tower crane); • locating the facility being constructed, and temporary structures: • eg: the building structure, a road, or • site offices, scaffolding; • space buffers; • eg: safety zone around hazardous operations, or space to prevent interference between tasks; • others?
Types of space : • permanent space (is available from start to finish) • some parts of the site; • created space (only becomes available when a certain milestone in the construction is reached): • each newly constructed floor on a multi-story building; • consumed space (is available until a certain milestone is reached): • the part of a site where a structure is eventually built; • created-consumed space (a combination of the previous two types of space): • a floor in a building becomes available for access and storage after it has been constructed, but once the finishes have been completed (eg: carpets) then it can no longer be used for storage;
Measurement attributes of space: • linear • vertical (side of building used for a temporary elevator); • horizontal (access ways); • perimeters (edge of building used to gain access such as to locate scaffolding) • area: • vertical (walls used for supporting scaffolding); • horizontal (floor space used for storage); • volume: • warehouse where items can be stacked; Miscellaneous attributes of space: • is divisible/combinable: • a space can be divided for several different uses (eg: for storage of different types of material); • those same space locations could be combined at some other time to provide storage for a single large element; • space locations can be combined in different ways for different tasks.
We have to plan the usage of space carefully: • the demand for space is obviously affected by the schedule (similar to the productive resources - equipment, labor); • the demand for space on a construction project is high, yet space is usually very scarce (similar to the productive resources); • we do not want a schedule that places two objects or activities in the same space at the same time (in other words, a space resource cannot be shared between two tasks, similar to the productive resources); • we do not want a schedule that uses space in a way that leads to unnecessary interference between tasks (this problem is NOT relevant to productive resources); • we do not want to use space in a way that leads to excessive travel distances between storage points and activity locations (this problem is NOT relevant to productive resources).
From the above, space is a resource that has some objectives and constraints in common with productive resources: • Q: therefore, can we treat space as a regular resource and thus use resource leveling methods to satisfy the objectives and constraints on its usage? • if so, we could then integrate satisfying space usage simultaneously with the other objectives and constraints! • A: Yes, but it is NOT as straightforward as it may first appear:
How can we integrate planning of space into the overall planning of a project, using P3: • we can divide space into unit types, such as Perimeter ‘A1’, Access ‘B3’, and Storage ‘K32’ (resource definition); • generally, we will need one space unit type for each type of space interference that may occur; • then we can specify which activities require which space units to operate (resource assignment); • activities in conflict for space, will be assigned the same space resource unit type; • then we can specify the number of each type of space unit available (resource constraint specification); • then we could apply resource leveling to ensure that an optimal schedule is selected that does not violate the resource constraints.
Issues with this approach: • some space is created when a certain task is complete, while other space gets consumed when some task is started - how can P3 handle this? • by using a logical dependence link that ensures that the activities requiring the space cannot start until the activity that creates the space has finished; • there are some limitations to this solution, however (see lecture notes). • some space is divisible and combinable - how can P3 handle this? • by careful division of space into units;