 Hello friends. Today we are going to discuss about multiple activity chart. The learning outcome will be able to draw a multiple activity chart. You will be able to draw a multiple activity chart for man-machine interaction. The session will be in the following sequence. We will be going for the introduction, the significance and importance of the multiple activity chart, how to construct a multiple activity chart and we will be studying some examples of man-machine type multiple activity charts. What is a multiple activity chart? Well, a multiple activity chart is a chart on which the activities of more than one subject, worker or machines are each recorded on a common scale to show their internal relationship. As we know multiple activity chart is one of the recording techniques in the method study and the recording techniques are generally classified in the two categories. One is called as charts on a timescale and the chart without timescale. Multiple activity chart happens to be a chart with timescale and the different types of multiple activity charts are there. The first one is man-machine type chart where one operator is working on machine. It is a one-to-one correspondence like a lathe machine or a conventional drilling machine, conventional CNC machine where one operator is working on one machine. Another type is man-multi-machine type chart when a single operator is working on number of machines. Generally, this is the case where a atomette is there when the setting is done by operator and he can operate generally two or three machines at a time. Generally, in terms of a radial drilling machine also we have got such type of arrangement. Multiman on the same machine chart when a group of workers are working on a machine. Such cases are generally happening in the big planning machines or big presses where there will be two to four operators at four locations on the machine and all simultaneously operate the machine. So, such case is generally called as multiman and same machine chart and there is a multiman-multi-machine chart when group of operators are working on multiple machines. This is a general example in case of a group layout where we will find group of workers are working on a particular machine. This type of picture is generally commonly observed in case of a fixed position layout. The significance and importance of the multiple activity chart is the chart shows different activities of operator and machine on a common scale. It shows period of idleness on the part of the machine or the man. It is possible to arrange these activities so that such ineffective time is reduced. The whole purpose of multiple activity chart is where on a time scale we are trying to find out what is the utilization and occupancy of the operator and what is the utilization of the machine or the equipment. Ultimately we will be able to coming out with the what is the ineffective time or idle time of the operator or the machine and then we try to maximize the utilization of the either resource either operator or the machine or in some cases both of them simultaneously. The timing we are taking it on a time scale the timing should be accurate enough for the chart to be effective. It can also be used for the picture of operation performed simultaneously by worker and machines. In some cases if the layout is new or if you have a new equipment or a new machine installed in that and we are interested to find out how many operators are required for that particular machine then we will be able to by drawing a multiple activity chart we will be able to find out number of operators required for a particular given job. How to construct a multiple activity chart? The separate bars and columns are allocated for each subject. These subjects are placed against common time scale. Activities of worker and machines are recorded by shading the respective bars or the columns. Shading indicates the occupancy or the utilization and idleness is shown by the blank of that particular column. Then the activities are plotted in the sequence against a common time scale. Here is an example of a multiple activity chart where is a case of one operator one machine. Just look to the variety of columns. You will find that the first column is a time scale. Second is operator. The third column indicates the time required for that. This is the part of the operator. On the second the next column is indicating the time scale for the machine. Machine activity time required for that machine activity and finally what is the landmark of this. For example, first we start with the description. The time scale 0.2 is indicating that we are starting the watch and then we are starting that pick up the job from the rack. A job is picked from the rack and it is generally taking 0.2 minutes. All the time scales are shown in minutes. 0.2 minutes for the operator to take the job and pick up from the rack. In that case we are not doing anything on the machine so therefore naturally machine will be idle. Next part is 0.28 the time scale the kind of watch continuously goes on it is on cumulative basis. The operator is doing activity of loading the job in the machine. The time required for this will be the difference between this time and the previous time 0.28 minus 0.2 it will be 0.08 minutes will be the total time required for the operator to load the job. Again in this case machine remains idle. Next activity is switching on the machine. The time is showing as 0.36 and the total time required for that activity will be 0.08 minutes. In this case machine is also required because he is operating the machine therefore both are shown as in the hatched area and both are required both are occupied. Once the machine is started machine is put on the auto cycle therefore machining continues and machining part on auto cycle which takes around 1.5 minutes. In this case machine is working and operator is idle so therefore in the column of operator we are showing it as idle and machine we are showing it as busy or occupied. Once that is there the next activity will be pick up the part in which case the part is picked up and therefore it takes 0.05 times and the machine remains idle. Afterwards the job is picked and then job is kept in the tray again this case the time required by the operator is 0.05 minutes and the total time in the machine will be remain in this idle case. So, this will be the a single very short cycle activity of loading the job putting auto cycle and taking the job away from that. The total time distribution of this will be operator's working time will be 0.46 minutes idle time will be 1.5 minute machine time will be 1.66 working time and 0.3 minutes as the idle time. So, this will show the multiple activity chart that which particular operator or the machine is busy and how much time it is busy and how much time it is idle. The next is now we have to think of how to draw a multiple activity chart in the case of one operator and two machines. We have to think of it now this is an solution for your problem on the left hand scale we have got in the time scale. Then operator number one operator one machine number one machine number two we have to continue the same sequence of operations as we are doing it for one operator one machine. Only in this case the first operator will work on the machine number one in this case operator and machine number work machine number one will be working machine number two will be idle in that case afterwards once the machine number one is set on auto mode then operator will now naturally move to the machine number two and therefore, in the further case operator and machine number two will be busy once both machines are working it may happen that machines are running and the operator is idle. So, this way the cycle will continue only in this case initially when both the machines are at idle some portion of time machine number two will remain idle until the machine number one goes into the auto cycle. So, that will be the initial startup idle time for the machines. So, afterwards probably when the continuation of the shift we can adjust this balancing also and then we can continue for this particular point. The total time distribution in this such case will be operator total time will be three minutes idle time one minute machine number one 3.5 idle time 0.5 machine number two 2.5 minutes and idle time will be 1.5 minute. So, by this we will be able to find out the total percentage of operators time idle time on the machine number one idle time on the machine number two and we can think of whether the same operator can run third machine or fourth machine it may happen that we are running multiple machines what will be the idleness of the operator and what will be the idleness especially for the remaining machines of 1 2 3 and so on. Now, there is a big pretty typical a tricky question while utilizing the resource operator or machine the question is whether utilization of the machine should be given a priority or utilization of person should be given a priority. The answer is of course, tricky can you think of this and tell the answer the answer is it is not a straight forward answer like we have to give utilization of machine or utilization of person as a priority it depends upon the type and value of the resource. If the machine is of high value and the constraint resource then we have to go for the utilization of the machine and in the other case we have to go for the operator in such cases the machine is of high value machine time is constrained even it may be economical and productive to have two operators operating on a single machine because we want to get more machine running time as compared to the operator this can be possible by adjusting the setup and change all time for those cases. These are some of the references which are used thank you.