Engineering Manager and through the Holmes & Narver, Inc, staff to the AEC Resident Manager. A weekly summary of work accomplished was submitted by each Resident Inspector to the Principal Engineer who in turn supplied figures to the Statistical Department for use in reports, Stoppages of construction as a result of inspection activities occurred from time to time, Thus, for example, when it was determined that the coarse aggregates being used at the Engebi Batch Plant did not meet specifications on concrete, work was halted until a new source of aggregate could be opened, Likewise, paving operations were stopped on a few occasions because of poorly graded aggregates or because equipMent was not functioning properly. Other work stoppages involving for the most part form work and alignment, were of a minor nature, It might be noted that none of the work stoppages involved serious delays in construction activities, although this was not used as a criterian in the determination of whether or not work should be stopped because of inspection objections. Upon completion of a particular feature of construction work, the inspector was required to submit a set of drawings on which notation had been made during the progress of the work of all changes which occurred, These notations were used in connection with the preparation of as-built drawings, discussed below. STATISTICS AND REPORTS In September 1949, the Statistical Engineer arrived at the Jobsite to initiate regular progress reports on construction, He was made responsible for setting up amd maintaining physical completion reports, data, charts, and other accounts of construction for all Jobsite facilities, Until November 1949, daily narrative reports of construction were maintained and mailed to the Home Office each week, On November 12, 1949, a new report designed in the Home Office was substituted, It was the Construction Progress & Percent Completion Report, submitted semimonthly, and it usually consisted of some 60 pages. In addition, statistics for a report conforming to the SFO 25 report were teletyped from Jobsite to the Home Office on the 25th of each month, Copies of progress reports were supplied to the AEC Resident Engineer, The principal difficulties encountered in the preparation of these reports resulted from the constant changes in work requirements, lack of information concerning the complete scope of the work, and insufficiency of qualified personnel. It was virtually impossible to make accurate and meaningful percentage estimates of progress without knowledge of the scope of the work, which was continually changing. During the period from September 1949 through June 8, 1950, files were set up; an Engineering Change Order form devised; Daily Inspection Reports devised and put into use; and a system of control of classified engineering documents instituted. Forms and reports were designed for general engineering use, such as an As-Built Data Report, Building Completion Check List, Concrete Pour Approval, and Concrete Cylinder Test Report, Early in 1950, it had become apparent that the semimonthly progress reports were unsatisfactory because of the laborious work in compilation 5-33