CHAPTER X

PROGRESS CHARTS, SCHEDULING SYSTEMS, ETC.

INTRODUCTION

In this chapter are given representative examples of charts or figures for exemplifying graphically, scheduled performances, costs, progress of work, etc., etc., in connection with engineering work. It is hardly necessary to state that the graphical method of illustrating such data is, to the man of engineering training (and to the great majority of nontechnical men also), very much superior to an array of figures, or pages of written matter. It is, perhaps, also hardly necessary to repeat the fact that the charts used by one company can never successfully be appropriated "holus bolus" by another; the system used must always be modified according to results desired, conditions of working, the personal equation, etc., of the second party; in other words, the whole value of those published lies in their suggestive possibilities.

PROGRESS CHART FOR THE DRAWING OFFICE

Practically all drawing-office work is done under the compulsion of a time limit, frequently a very short one. A power plant has to be in operation at a certain date, or machinery has to be designed and fabricated in time to catch a certain steamer, and it is necessary that drawings be prepared, and orders placed sufficiently in advance of these dates, so that promises may be fulfilled. In a small office, where only one or two jobs are carried through at one time, there may be little trouble in meeting such dates; but in larger offices, handling a dozen or more jobs at one time, some system of advance planning is imperative.

One of the most usual methods of scheduling work, not only in the draughting room but also in other departments, is by the use of chronologically divided charts.

A so-called "Progress Chart" that has been tested-out for several years in the office of a firm of consulting and contracting engineers engaged on export work, and which has proven itself satisfactory, is shown in Fig. 153.

The key at the top of the chart explains the meaning of the symbols, and the chronological division by (approximate) weeks is apparent.

The method of working consists in first of all making out a list of the main items of machinery or work and placing them in some convenient

letter "O," indicating date at which order must be placed, is next located

in red a corresponding time before the "S." If it will take 2 weeks or a month to obtain bids and place an order after the drawings and specifications leave the office, the date at which they should be sent out can thus be indicated by a red "D" sufficiently in advance of the "O."

RESP

order in the left-hand column of the sheet. Then, using red ink or a red pencil, the shipping date for each item is indicated on the chart by the letter "S" in the case of material, or "d" in the case of drawings. Knowing from past records the probable time required to obtain delivery, the

Notes; Actual (N. Y.) Shipments

June 7, July 24 & Sep.2.

Delivery F.A.S./Erected at N. Y.Harbor

FIG. 153. Progress chart for drawing office work.

Finally, the date at which it will be necessary to start such drawings can be indicated by a red "X." Red lines should then be drawn connecting the "X" with the "D" in order that the "vital period" may be more forcibly expressed.

An inspection of the chart thus prepared will show the chief draftsman at a glance the magnitude of the work ahead of him. Any large bunching of red lines at one period will point to a probable required enlargement of the drawing-office force for that time. Or again, if the regular force is larger than necessary for the indications at the first stages of the work, the "X," "D" and "O" for certain items may be advanced in time, with the double advantage that the office work may be more

FIG. 154.-Display board for drawing office progress charts.

evenly distributed, and that better terms may be obtained from the manufacturers consequent on the delayed delivery conceded. A further advantage is the guarantee afforded against forgetting any item of importance in the installation.

In practice, of course, many conditions will arise to alter the ideal schedule; sickness, delayed information, strikes, etc., cannot well be foreseen, but these uncertainties are not sufficiently great to counteract in any large degree the value of the schedule.

Continuing the subject of the method of working: As the drawings are sent out and orders placed, these events may be noted by the marks "D" and "O" in black ink at the proper place in the chart. At the time that the black "O" is marked, the letters "A" (contractor's drawings approved) and "d" (drawings to the field) should be placed in red. These letters in black show that this part of the work has been disposed

of, and they are also valuable, for future schedule planning, in indicating the time that was actually required to do the work.

At convenient intervals, say once a week, the chief draftsman, by running down the list, may inform himself of the progress of the job and may make notes and issue orders to hurry along any part that may be falling behind the schedule. A pencil check-mark at the head of the list may be used to indicate when such inspection was made. When the material has been shipped and drawings sent to the works (indicated by black "S" and "d"), a blue check-mark at the end of the line will show that the work on that item is closed.

Now taking up the mechanical features of the system: The charts may be prepared either on stout "white mounting boards," on paper or on tracing cloth; the latter is useful when copies are required at intervals, but the former is usually preferable, and photo-reproductions may be made of the boards if necessary. The sheets may be about 14 in. wide X 11 in. high for small jobs, and 22 in. high for larger jobs, and several sheets for one job may be used if necessary. It is often advantageous to hang the sheets in such a manner that they may be readily visible from the office chair. A convenient method of so displaying the charts is shown in Fig. 154. The board illustrated is 2 ft. × 5 ft. in size, 3/4 in. thick, made of white wood with matched end-pieces, finished all over and shellacked. The charts are hung on small hooks, so that they can be readily removed. The board can be hung from the picture-molding by wire and screw-eyes.

THE SCHEDULING SYSTEM OF A Large LOCOMOTIVE WORKS

The following description is taken from an article on "The Draftingroom System of the American Locomotive Co." by Mr. Fred. H. Moody in "Machinery" for June, 1911. It illustrates very clearly the methods. employed by a large manufacturing establishment in turning out its contracts on scheduled time.

"While the specifications are being compiled, the process of scheduling the work is under way. The contract specification usually states a time delivery for the locomotives. The form for scheduling is shown in Fig. 155, which shows the schedule card for the locomotive on an 80-day basis; similar cards are made out for the tender. On this schedule form complete information is given, but the principal feature to be noted, however, is the scheduling. All the productive work is divided into three general groups: "A," material and specifications; "B," new and old patterns and flanging dies; and "C," cards and sketches.

"A little consideration will make it clear that different lengths of time are required for making any particular part, depending upon such factors as the amount of machine work, whether it is purchased on the outside, and other equally important considerations. From long experience the company has been able to

form a general schedule showing how long previous to the delivery date it is necessary to have the different details ready. This has been prepared in the department for various delivery periods, ranging from 105 down to 40 days, the former length of time being generally required for new designs, while a repetition

FIG. 155.-General schedule of engine for the drafting room.

order may be completed within the latter time period, from the fact that in the latter case all drawings, patterns, etc., are ready. Consider an 80-day delivery: From this general schedule the engineer knows just how much time any part requires; from a computing calendar a date for any number of working days ahead

FIG. 156.-Minor schedule card for section use (Am. Loco. Co's. Drawing Office). can be readily determined. Take, for example, "axles" on an 80-day basis; the material for these must be ordered among the first things. This is shown by the cipher opposite "axles" under list "A" of the 80-day column. The date is placed in the vacant space just above, under the squares containing "75, 70, 65,