1 00:00:00,006 --> 00:00:01,009 - [Instructor] Requirement analysis 2 00:00:01,009 --> 00:00:05,004 needs system functionalities specified in some form. 3 00:00:05,004 --> 00:00:08,003 Either use cases or user stories. 4 00:00:08,003 --> 00:00:10,000 Analyzing user stories, 5 00:00:10,000 --> 00:00:12,007 helps identify conditions of satisfaction 6 00:00:12,007 --> 00:00:16,000 or acceptance criteria for the functionality, 7 00:00:16,000 --> 00:00:18,009 and analyzing use case specifications 8 00:00:18,009 --> 00:00:21,004 helps us identify domain classes, 9 00:00:21,004 --> 00:00:24,001 their attributes and associations. 10 00:00:24,001 --> 00:00:26,004 This gives us domain diagrams 11 00:00:26,004 --> 00:00:28,002 that are structural representation 12 00:00:28,002 --> 00:00:30,001 of our system in terms of, 13 00:00:30,001 --> 00:00:32,006 key entities and their attributes. 14 00:00:32,006 --> 00:00:35,006 These entities most often translate into, 15 00:00:35,006 --> 00:00:38,004 design classes and database tables. 16 00:00:38,004 --> 00:00:41,005 From the use case diagrams that we created, 17 00:00:41,005 --> 00:00:46,001 let me pick one which I will use just as an example here. 18 00:00:46,001 --> 00:00:48,004 One of the simplest ones here 19 00:00:48,004 --> 00:00:51,009 is the search food products use case. 20 00:00:51,009 --> 00:00:55,000 Let us look at its user story first. 21 00:00:55,000 --> 00:00:57,007 Following the standard user story format, 22 00:00:57,007 --> 00:00:59,003 we can write it as, 23 00:00:59,003 --> 00:01:03,003 as a user, I want to search for a food product by name, 24 00:01:03,003 --> 00:01:06,003 so that I can see its nutritional value. 25 00:01:06,003 --> 00:01:07,008 What this means is that, 26 00:01:07,008 --> 00:01:10,005 not only we need to do a product search 27 00:01:10,005 --> 00:01:13,008 but we also need to show its nutrients. 28 00:01:13,008 --> 00:01:18,003 And here is the use case specification for such use case. 29 00:01:18,003 --> 00:01:21,004 The primary actor is any user here 30 00:01:21,004 --> 00:01:23,006 and the secondary actor, is the database 31 00:01:23,006 --> 00:01:25,006 to be used for searching. 32 00:01:25,006 --> 00:01:29,007 For now, we are thinking of using the database from USDA. 33 00:01:29,007 --> 00:01:33,000 The precondition is that, user should be able to access 34 00:01:33,000 --> 00:01:35,009 the web application over the internet. 35 00:01:35,009 --> 00:01:39,002 In basic flow, user chooses the search option 36 00:01:39,002 --> 00:01:42,003 and Red30 asks to enter a search string. 37 00:01:42,003 --> 00:01:44,007 Once user enters the search string, 38 00:01:44,007 --> 00:01:47,000 Red30 displays the product names 39 00:01:47,000 --> 00:01:49,009 that have that search string in their names 40 00:01:49,009 --> 00:01:54,001 and also the nutrients and their quantities in them. 41 00:01:54,001 --> 00:01:55,009 The alternate flow could be 42 00:01:55,009 --> 00:01:58,009 that Red30 doesn't find anything with matching names 43 00:01:58,009 --> 00:02:01,006 and accordingly displays a message. 44 00:02:01,006 --> 00:02:03,004 Writing the use case in this way, 45 00:02:03,004 --> 00:02:05,006 helps us see the flow of interaction 46 00:02:05,006 --> 00:02:08,004 between the user and the system. 47 00:02:08,004 --> 00:02:11,008 We can now move on to creating a domain diagram 48 00:02:11,008 --> 00:02:15,007 in which we identify, key nouns, their properties, 49 00:02:15,007 --> 00:02:18,007 and possible relationships among them. 50 00:02:18,007 --> 00:02:23,003 As an example, if I take this excerpt from the use case, 51 00:02:23,003 --> 00:02:28,001 I find food products and nutrients as two key nouns 52 00:02:28,001 --> 00:02:31,007 that can become possible entities in our system. 53 00:02:31,007 --> 00:02:34,006 Food product has an attribute name 54 00:02:34,006 --> 00:02:37,002 and also a list of nutrients. 55 00:02:37,002 --> 00:02:39,005 We can also infer from this text 56 00:02:39,005 --> 00:02:40,009 that nutrients are present 57 00:02:40,009 --> 00:02:43,004 in products in certain quantities. 58 00:02:43,004 --> 00:02:46,004 So this gives us, two domain classes. 59 00:02:46,004 --> 00:02:48,002 Product and nutrient. 60 00:02:48,002 --> 00:02:51,004 Product has product name and nutrients 61 00:02:51,004 --> 00:02:54,002 and nutrient has name and quantity. 62 00:02:54,002 --> 00:02:57,004 The association between them is aggregation, 63 00:02:57,004 --> 00:03:00,003 as product contains nutrients. 64 00:03:00,003 --> 00:03:03,008 Now, that gives us possible classes when we get to design. 65 00:03:03,008 --> 00:03:06,006 And also to our data modeling. 66 00:03:06,006 --> 00:03:08,004 But before we go there, 67 00:03:08,004 --> 00:03:11,005 we need to continuously check for two things. 68 00:03:11,005 --> 00:03:13,006 First, whatever we are building, 69 00:03:13,006 --> 00:03:15,007 we are building it in the right way, 70 00:03:15,007 --> 00:03:19,004 and second, that we are building the right thing. 71 00:03:19,004 --> 00:03:22,001 To assess whether we are building in the right way, 72 00:03:22,001 --> 00:03:26,002 pertains to using correct methodology, tools and techniques. 73 00:03:26,002 --> 00:03:29,009 It also requires assessing architectural feasibility, 74 00:03:29,009 --> 00:03:32,008 which means coming up with a high level architecture, 75 00:03:32,008 --> 00:03:35,008 and, then developing a proof of concept 76 00:03:35,008 --> 00:03:38,002 to check if it works. 77 00:03:38,002 --> 00:03:41,003 To assess whether we are building the right thing, 78 00:03:41,003 --> 00:03:44,001 the best way is to show it to our customer 79 00:03:44,001 --> 00:03:46,000 and seek their feedback. 80 00:03:46,000 --> 00:03:49,009 This reduces project risk and gives us more confidence. 81 00:03:49,009 --> 00:03:53,008 So, let us do these two things for our Red30 product. 82 00:03:53,008 --> 00:03:57,005 First, let us see what we want to show to our customer. 83 00:03:57,005 --> 00:04:01,003 We can show our customer a low fidelity mockup, 84 00:04:01,003 --> 00:04:02,006 drawn on a paper 85 00:04:02,006 --> 00:04:06,002 which focuses mainly on structure for a rough idea 86 00:04:06,002 --> 00:04:09,003 or, we can have a high fidelity prototype 87 00:04:09,003 --> 00:04:11,002 that focuses on user experience 88 00:04:11,002 --> 00:04:13,005 for a real look and feel. 89 00:04:13,005 --> 00:04:16,001 For this case study, I'm going to build a mockup 90 00:04:16,001 --> 00:04:18,005 using a tool called balsamiq 91 00:04:18,005 --> 00:04:21,009 which makes it a little more formal than a paper mockup 92 00:04:21,009 --> 00:04:25,002 and also gives some idea about look and feel. 93 00:04:25,002 --> 00:04:28,001 In balsamiq you can create your projects, 94 00:04:28,001 --> 00:04:31,008 and then within each project, you can create wireframes. 95 00:04:31,008 --> 00:04:34,004 These wireframes have various components 96 00:04:34,004 --> 00:04:37,008 such as hyperlinks, text, buttons et cetera, 97 00:04:37,008 --> 00:04:40,006 which you can link to create the kind of workflow 98 00:04:40,006 --> 00:04:43,000 that you want to show to your customer. 99 00:04:43,000 --> 00:04:45,008 As you can see I have created several wireframes 100 00:04:45,008 --> 00:04:48,001 that capture key use cases of search, 101 00:04:48,001 --> 00:04:50,008 compare, login, record meal, 102 00:04:50,008 --> 00:04:53,006 view diet log and track nutrition. 103 00:04:53,006 --> 00:04:55,008 These wireframes are rough sketches 104 00:04:55,008 --> 00:04:59,003 of what I will actually build over next few iterations. 105 00:04:59,003 --> 00:05:01,009 You could start with just one of the wireframes, 106 00:05:01,009 --> 00:05:04,002 and build the rest over sprints, 107 00:05:04,002 --> 00:05:06,000 or you could create several of them 108 00:05:06,000 --> 00:05:08,006 if you have enough clarity at this point. 109 00:05:08,006 --> 00:05:10,008 The idea is to keep them simple, 110 00:05:10,008 --> 00:05:12,009 and always be open to change them 111 00:05:12,009 --> 00:05:14,009 as your project progresses. 112 00:05:14,009 --> 00:05:18,001 I will run this wireframe now, 113 00:05:18,001 --> 00:05:22,009 which will take me to first wireframe, showing the homepage. 114 00:05:22,009 --> 00:05:26,000 From there, I select search 115 00:05:26,000 --> 00:05:28,001 which takes me to search box 116 00:05:28,001 --> 00:05:31,008 and let's say I enter tomato basil soup here, 117 00:05:31,008 --> 00:05:33,005 this gives me all products 118 00:05:33,005 --> 00:05:35,006 with tomato basil soup in their names 119 00:05:35,006 --> 00:05:38,008 along with their manufacturer's brand names. 120 00:05:38,008 --> 00:05:41,007 At this point, I have put some fake data here 121 00:05:41,007 --> 00:05:44,006 and there is no back-end linked to any database. 122 00:05:44,006 --> 00:05:46,004 There is a selection radio button, 123 00:05:46,004 --> 00:05:48,003 on the right of each of these 124 00:05:48,003 --> 00:05:52,000 and the table at the bottom shows nutrients in hundred units 125 00:05:52,000 --> 00:05:53,008 of the selected product. 126 00:05:53,008 --> 00:05:56,001 If I select the second product, 127 00:05:56,001 --> 00:05:59,004 I can see the nutrients for the new selected product. 128 00:05:59,004 --> 00:06:02,009 In this way, this mockup shows screen transitions 129 00:06:02,009 --> 00:06:07,000 with some sample data for first two products. 130 00:06:07,000 --> 00:06:08,007 If I show it to my customer, 131 00:06:08,007 --> 00:06:12,002 it is easier for them to ask questions such as changes 132 00:06:12,002 --> 00:06:16,000 or point out any mistakes I may have made. 133 00:06:16,000 --> 00:06:18,003 Another benefit of using such a tool 134 00:06:18,003 --> 00:06:20,006 is that you can share the link of this mockup 135 00:06:20,006 --> 00:06:23,006 with your team members as well as your customers, 136 00:06:23,006 --> 00:06:25,008 and ask them to try it out. 137 00:06:25,008 --> 00:06:29,000 A great way to get a quick well-rounded feedback 138 00:06:29,000 --> 00:06:31,000 from all your stakeholders.