| Task ID | Task Name                                                  |
|---------|------------------------------------------------------------|
| a       | Background study on e-payment implementation               |
| b       | Collect detailed requirements                              |
| c       | Develop prototype to show payment procedure                |
| d       | Design overall software architecture                       |
| e       | Design database                                            |
| f       | Design end-user interfaces on mobile phones                |
| g       | Design admin interfaces on desktop computers               |
| h       | Design signal connection with bike locks                   |
| i       | Design security scheme for internet transactions           |
| j       | Develop interface templates for sponsor review             |
| k       | Create site map/hierarchy chart                            |
| l       | Create individual web pages                                |
| m       | Create database                                            |
| n       | Source necessary library modules for client-side coding    |
| o       | Purchase bike locks for testing                            |
| p       | Code server-side modules #40;system admin and operations#41;         |
| q       | Code server-side modules #40;end-user services#41;                  |
| r       | Code client-side modules #40;system admin and operations#41;         |
| s       | Code client-side modules #40;end-user services#41;                  |
| t       | Integrate server-side modules and web pages                |
| u       | Test connection to bike locks with shared-bike app         |
| v       | Performance stress tests on the system                     |
| w       | Conduct UAT with sponsor and end-user representatives      |
| x       | Install website on government's web server                 |
| y       | Create technical training materials                        |
| z       | Train staff in operating and maintaining the system        |

```Early Start
gantt
    dateFormat  DD-MM-YYYY
    title Project Schedule

    %% Milestones
    section Milestones
    Prototype Delivery Milestone        :milestone, m1, 01-03-2024, 0d
    Intermediate Modules Milestone      :milestone, m2, 01-06-2024, 0d
    Project Completion Milestone        :milestone, m3, 01-09-2024, 0d

    section Analysis
    a :a, 01-01-2024, 15d
    b :b, after a, 20d
    c :c, after b, 20d
    milestonec :milestone, m1, after c, 0d

    section Design
    d :d, after b, 25d
    e :e, after d, 10d
    f :f, after d, 20d
    g :g, after f, 10d
    h :h, after d, 10d
    i :i, after d, 15d
    j :j, after f and g, 10d
    k :k, after j, 10d

    section Implementation
    l :l, after k, 30d
    m :m, after e, 15d
    n :n, after f, 15d
    o :o, after h, 10d
    p :p, after i and g,20d
    q :q, after i,25d
    r :r, after n,20d
    s :s, after n,20d
    t :t, after l and m and p and q and r and s, 15d
    milestonei :milestone, m2, after t, 0d

    section Deployment
    u :u, after t and o, 5d
    v :v, after u,5d
    w :w, after v,5d
    x :x, after w,10d
    y :y, after x,20d
    z :z, after y,18d
    milestonef :milestone, m3, after z, 0d
```

```Late Start
gantt
    dateFormat  DD-MM-YYYY
    title Revised Project Schedule (Late Start)

    %% Milestones
    section Milestones
    Prototype Delivery Milestone        :milestone, m1, 01-03-2024, 0d
    Intermediate Modules Milestone      :milestone, m2, 01-06-2024, 0d
    Project Completion Milestone        :milestone, m3, 01-09-2024, 0d

    section Analysis
    a :a, 01-01-2024, 18d
    b :b, after a, 20d
    c :c, after b, 22d
    milestonec :milestone, m1, after c, 0d

    section Design
    d :d, after b, 25d
    e :e, after d, 15d
    f :f, after d, 25d
    g :g, after f, 15d
    h :h, after d, 15d
    i :i, after d, 20d
    j :j, after f and g, 12d
    k :k, after j, 12d

    section Implementation
    l :l, after k, 30d
    m :m, after e, 20d
    n :n, after f, 20d
    o :o, after h, 12d
    p :p, after i and g,25d
    q :q, after i,30d
    r :r, after n,25d
    s :s, after n,25d
    t :t, after l and m and p and q and r and s, 20d
    milestonei :milestone, m2, after t, 0d

    section Deployment
    u :u, after t and o, 5d
    v :v, after u,5d
    w :w, after v,5d
    x :x, after w,12d
    y :y, after x,20d
    z :z, after y,20d
    milestonef :milestone, m3, after z, 0d
```

base on two charts to build the table:

| Task | Duration (Days) | ΔDuration (Days) |
|---|---|---|---|---|---|
| a | 15 | 2 | - | 0 | 15 |