schedules, errors in these estimates can multiply many times. Be careful in their preparation!
A material estimate consists of a listing and description of the various materials and the quantities required to construct a given project. Information for preparing material estimates is obtained from the activity estimates, drawings, and specifications. A material estimate is sometimes referred to as "a Bill of Material (BM)" or "a Material Takeoff (MTO) Sheet." (We will discuss the BM and the MTO a little later in the chapter.)
Equipment estimates are listings of the various types of equipment, the amount of time, and the number of pieces of equipment required to construct a given project. Information, such as that obtained from activity estimates, drawings, specifications, and an inspection of the site, provides the basis for preparing the equipment estimates.
The manpower estimate consists of a listing of the number of direct labor man-days required to complete the various activities of a specific project. These estimates may show only the man-days for each activity, or they may be in sufficient detail to list the number of man-days for each rating in each activity - Builder (BU), Construction Electrician (CE), Equipment Operator (EO), Steelworker (SW), and Utilitiesman (UT). Man-day estimates are used in determining the number of personnel and the ratings required on a deployment. They also provide the basis for scheduling manpower in relation to construction progress.
When the Seabee Planner's and Estimator's Handbook, NAVFAC P-405, is used, a man-day is a unit of work performed by one person in one 8-hour day or its equivalent. One man-day is equivalent to a 10-hour day when the Facilities Planning Guide, NAVFAC P-437, is used.
Battalions set their own schedules, as needed, to complete their assigned tasks. In general, the work schedule of the battalion is based on an average of 55 hours per man per week. The duration of the workday is 10 hours per day, which starts and ends at the jobsite. This includes 9 hours for direct labor and 1 hour for lunch.
Direct labor includes all labor expended directly on assigned construction tasks, either in the field or in the shop, that contributes directly to the completion of the end product. Direct labor must be reported separately for each assigned construction item. In addition to direct labor, the estimator must also consider overhead labor and indirect labor. Overhead labor is considered productive labor that does not contribute directly or indirectly to the product. It includes all labor that must be performed regardless of the assigned mission. Indirect labor includes labor required to support construction operations but does not, in itself, produce an end product.
An estimator is a person who evaluates the requirements of a task. A construction estimator must be able to mentally picture the separate operations of the job as the work progresses through the various stages of construction and be able to read and obtain accurate measurements from drawings. The estimator must have an understanding of math, previous construction experience, and a working knowledge of all branches of construction. The estimator must use good judgment when determining what effect numerous factors and conditions have on construction of the project and what allowances should be made for each of them. The estimator must be able to do careful and accurate work. A Seabee estimator must have ready access to information about the material, equipment, and labor required to perform various types of work under conditions encountered in Seabee deployments. The collection of such information on construction performance is part of estimating. Since this kind of reference information may change from time to time, information should be frequently reviewed.
Scheduling is the process of determining when an action must be taken and when material, equipment, and manpower are required. There are four basic types of schedules: progress, material, equipment, and manpower.
Progress schedules coordinate all the projects of a Seabee deployment or all the activities of a single project. They show the sequence, the starting time, the performance time required, and the time requiredContinue Reading